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alistair23-linux/arch/powerpc/kvm/book3s_xive_native.c

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// SPDX-License-Identifier: GPL-2.0
/*
* Copyright (c) 2017-2019, IBM Corporation.
*/
#define pr_fmt(fmt) "xive-kvm: " fmt
#include <linux/kernel.h>
#include <linux/kvm_host.h>
#include <linux/err.h>
#include <linux/gfp.h>
#include <linux/spinlock.h>
#include <linux/delay.h>
KVM: PPC: Book3S HV: XIVE: Add passthrough support The KVM XICS-over-XIVE device and the proposed KVM XIVE native device implement an IRQ space for the guest using the generic IPI interrupts of the XIVE IC controller. These interrupts are allocated at the OPAL level and "mapped" into the guest IRQ number space in the range 0-0x1FFF. Interrupt management is performed in the XIVE way: using loads and stores on the addresses of the XIVE IPI interrupt ESB pages. Both KVM devices share the same internal structure caching information on the interrupts, among which the xive_irq_data struct containing the addresses of the IPI ESB pages and an extra one in case of pass-through. The later contains the addresses of the ESB pages of the underlying HW controller interrupts, PHB4 in all cases for now. A guest, when running in the XICS legacy interrupt mode, lets the KVM XICS-over-XIVE device "handle" interrupt management, that is to perform the loads and stores on the addresses of the ESB pages of the guest interrupts. However, when running in XIVE native exploitation mode, the KVM XIVE native device exposes the interrupt ESB pages to the guest and lets the guest perform directly the loads and stores. The VMA exposing the ESB pages make use of a custom VM fault handler which role is to populate the VMA with appropriate pages. When a fault occurs, the guest IRQ number is deduced from the offset, and the ESB pages of associated XIVE IPI interrupt are inserted in the VMA (using the internal structure caching information on the interrupts). Supporting device passthrough in the guest running in XIVE native exploitation mode adds some extra refinements because the ESB pages of a different HW controller (PHB4) need to be exposed to the guest along with the initial IPI ESB pages of the XIVE IC controller. But the overall mechanic is the same. When the device HW irqs are mapped into or unmapped from the guest IRQ number space, the passthru_irq helpers, kvmppc_xive_set_mapped() and kvmppc_xive_clr_mapped(), are called to record or clear the passthrough interrupt information and to perform the switch. The approach taken by this patch is to clear the ESB pages of the guest IRQ number being mapped and let the VM fault handler repopulate. The handler will insert the ESB page corresponding to the HW interrupt of the device being passed-through or the initial IPI ESB page if the device is being removed. Signed-off-by: Cédric Le Goater <clg@kaod.org> Reviewed-by: David Gibson <david@gibson.dropbear.id.au> Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2019-04-18 04:39:39 -06:00
#include <linux/file.h>
#include <asm/uaccess.h>
#include <asm/kvm_book3s.h>
#include <asm/kvm_ppc.h>
#include <asm/hvcall.h>
#include <asm/xive.h>
#include <asm/xive-regs.h>
#include <asm/debug.h>
#include <asm/debugfs.h>
#include <asm/opal.h>
#include <linux/debugfs.h>
#include <linux/seq_file.h>
#include "book3s_xive.h"
static u8 xive_vm_esb_load(struct xive_irq_data *xd, u32 offset)
{
u64 val;
if (xd->flags & XIVE_IRQ_FLAG_SHIFT_BUG)
offset |= offset << 4;
val = in_be64(xd->eoi_mmio + offset);
return (u8)val;
}
static void kvmppc_xive_native_cleanup_queue(struct kvm_vcpu *vcpu, int prio)
{
struct kvmppc_xive_vcpu *xc = vcpu->arch.xive_vcpu;
struct xive_q *q = &xc->queues[prio];
xive_native_disable_queue(xc->vp_id, q, prio);
if (q->qpage) {
put_page(virt_to_page(q->qpage));
q->qpage = NULL;
}
}
void kvmppc_xive_native_cleanup_vcpu(struct kvm_vcpu *vcpu)
{
struct kvmppc_xive_vcpu *xc = vcpu->arch.xive_vcpu;
int i;
if (!kvmppc_xive_enabled(vcpu))
return;
if (!xc)
return;
pr_devel("native_cleanup_vcpu(cpu=%d)\n", xc->server_num);
/* Ensure no interrupt is still routed to that VP */
xc->valid = false;
kvmppc_xive_disable_vcpu_interrupts(vcpu);
/* Disable the VP */
xive_native_disable_vp(xc->vp_id);
/* Free the queues & associated interrupts */
for (i = 0; i < KVMPPC_XIVE_Q_COUNT; i++) {
/* Free the escalation irq */
if (xc->esc_virq[i]) {
free_irq(xc->esc_virq[i], vcpu);
irq_dispose_mapping(xc->esc_virq[i]);
kfree(xc->esc_virq_names[i]);
xc->esc_virq[i] = 0;
}
/* Free the queue */
kvmppc_xive_native_cleanup_queue(vcpu, i);
}
/* Free the VP */
kfree(xc);
/* Cleanup the vcpu */
vcpu->arch.irq_type = KVMPPC_IRQ_DEFAULT;
vcpu->arch.xive_vcpu = NULL;
}
int kvmppc_xive_native_connect_vcpu(struct kvm_device *dev,
struct kvm_vcpu *vcpu, u32 server_num)
{
struct kvmppc_xive *xive = dev->private;
struct kvmppc_xive_vcpu *xc = NULL;
int rc;
pr_devel("native_connect_vcpu(server=%d)\n", server_num);
if (dev->ops != &kvm_xive_native_ops) {
pr_devel("Wrong ops !\n");
return -EPERM;
}
if (xive->kvm != vcpu->kvm)
return -EPERM;
if (vcpu->arch.irq_type != KVMPPC_IRQ_DEFAULT)
return -EBUSY;
if (server_num >= KVM_MAX_VCPUS) {
pr_devel("Out of bounds !\n");
return -EINVAL;
}
mutex_lock(&vcpu->kvm->lock);
if (kvmppc_xive_find_server(vcpu->kvm, server_num)) {
pr_devel("Duplicate !\n");
rc = -EEXIST;
goto bail;
}
xc = kzalloc(sizeof(*xc), GFP_KERNEL);
if (!xc) {
rc = -ENOMEM;
goto bail;
}
vcpu->arch.xive_vcpu = xc;
xc->xive = xive;
xc->vcpu = vcpu;
xc->server_num = server_num;
xc->vp_id = kvmppc_xive_vp(xive, server_num);
xc->valid = true;
vcpu->arch.irq_type = KVMPPC_IRQ_XIVE;
rc = xive_native_get_vp_info(xc->vp_id, &xc->vp_cam, &xc->vp_chip_id);
if (rc) {
pr_err("Failed to get VP info from OPAL: %d\n", rc);
goto bail;
}
/*
* Enable the VP first as the single escalation mode will
* affect escalation interrupts numbering
*/
rc = xive_native_enable_vp(xc->vp_id, xive->single_escalation);
if (rc) {
pr_err("Failed to enable VP in OPAL: %d\n", rc);
goto bail;
}
/* Configure VCPU fields for use by assembly push/pull */
vcpu->arch.xive_saved_state.w01 = cpu_to_be64(0xff000000);
vcpu->arch.xive_cam_word = cpu_to_be32(xc->vp_cam | TM_QW1W2_VO);
/* TODO: reset all queues to a clean state ? */
bail:
mutex_unlock(&vcpu->kvm->lock);
if (rc)
kvmppc_xive_native_cleanup_vcpu(vcpu);
return rc;
}
KVM: PPC: Book3S HV: XIVE: Add passthrough support The KVM XICS-over-XIVE device and the proposed KVM XIVE native device implement an IRQ space for the guest using the generic IPI interrupts of the XIVE IC controller. These interrupts are allocated at the OPAL level and "mapped" into the guest IRQ number space in the range 0-0x1FFF. Interrupt management is performed in the XIVE way: using loads and stores on the addresses of the XIVE IPI interrupt ESB pages. Both KVM devices share the same internal structure caching information on the interrupts, among which the xive_irq_data struct containing the addresses of the IPI ESB pages and an extra one in case of pass-through. The later contains the addresses of the ESB pages of the underlying HW controller interrupts, PHB4 in all cases for now. A guest, when running in the XICS legacy interrupt mode, lets the KVM XICS-over-XIVE device "handle" interrupt management, that is to perform the loads and stores on the addresses of the ESB pages of the guest interrupts. However, when running in XIVE native exploitation mode, the KVM XIVE native device exposes the interrupt ESB pages to the guest and lets the guest perform directly the loads and stores. The VMA exposing the ESB pages make use of a custom VM fault handler which role is to populate the VMA with appropriate pages. When a fault occurs, the guest IRQ number is deduced from the offset, and the ESB pages of associated XIVE IPI interrupt are inserted in the VMA (using the internal structure caching information on the interrupts). Supporting device passthrough in the guest running in XIVE native exploitation mode adds some extra refinements because the ESB pages of a different HW controller (PHB4) need to be exposed to the guest along with the initial IPI ESB pages of the XIVE IC controller. But the overall mechanic is the same. When the device HW irqs are mapped into or unmapped from the guest IRQ number space, the passthru_irq helpers, kvmppc_xive_set_mapped() and kvmppc_xive_clr_mapped(), are called to record or clear the passthrough interrupt information and to perform the switch. The approach taken by this patch is to clear the ESB pages of the guest IRQ number being mapped and let the VM fault handler repopulate. The handler will insert the ESB page corresponding to the HW interrupt of the device being passed-through or the initial IPI ESB page if the device is being removed. Signed-off-by: Cédric Le Goater <clg@kaod.org> Reviewed-by: David Gibson <david@gibson.dropbear.id.au> Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2019-04-18 04:39:39 -06:00
/*
* Device passthrough support
*/
static int kvmppc_xive_native_reset_mapped(struct kvm *kvm, unsigned long irq)
{
struct kvmppc_xive *xive = kvm->arch.xive;
if (irq >= KVMPPC_XIVE_NR_IRQS)
return -EINVAL;
/*
* Clear the ESB pages of the IRQ number being mapped (or
* unmapped) into the guest and let the the VM fault handler
* repopulate with the appropriate ESB pages (device or IC)
*/
pr_debug("clearing esb pages for girq 0x%lx\n", irq);
mutex_lock(&xive->mapping_lock);
if (xive->mapping)
unmap_mapping_range(xive->mapping,
irq * (2ull << PAGE_SHIFT),
2ull << PAGE_SHIFT, 1);
mutex_unlock(&xive->mapping_lock);
return 0;
}
static struct kvmppc_xive_ops kvmppc_xive_native_ops = {
.reset_mapped = kvmppc_xive_native_reset_mapped,
};
static vm_fault_t xive_native_esb_fault(struct vm_fault *vmf)
{
struct vm_area_struct *vma = vmf->vma;
struct kvm_device *dev = vma->vm_file->private_data;
struct kvmppc_xive *xive = dev->private;
struct kvmppc_xive_src_block *sb;
struct kvmppc_xive_irq_state *state;
struct xive_irq_data *xd;
u32 hw_num;
u16 src;
u64 page;
unsigned long irq;
u64 page_offset;
/*
* Linux/KVM uses a two pages ESB setting, one for trigger and
* one for EOI
*/
page_offset = vmf->pgoff - vma->vm_pgoff;
irq = page_offset / 2;
sb = kvmppc_xive_find_source(xive, irq, &src);
if (!sb) {
pr_devel("%s: source %lx not found !\n", __func__, irq);
return VM_FAULT_SIGBUS;
}
state = &sb->irq_state[src];
kvmppc_xive_select_irq(state, &hw_num, &xd);
arch_spin_lock(&sb->lock);
/*
* first/even page is for trigger
* second/odd page is for EOI and management.
*/
page = page_offset % 2 ? xd->eoi_page : xd->trig_page;
arch_spin_unlock(&sb->lock);
if (WARN_ON(!page)) {
pr_err("%s: accessing invalid ESB page for source %lx !\n",
__func__, irq);
return VM_FAULT_SIGBUS;
}
vmf_insert_pfn(vma, vmf->address, page >> PAGE_SHIFT);
return VM_FAULT_NOPAGE;
}
static const struct vm_operations_struct xive_native_esb_vmops = {
.fault = xive_native_esb_fault,
};
static vm_fault_t xive_native_tima_fault(struct vm_fault *vmf)
{
struct vm_area_struct *vma = vmf->vma;
switch (vmf->pgoff - vma->vm_pgoff) {
case 0: /* HW - forbid access */
case 1: /* HV - forbid access */
return VM_FAULT_SIGBUS;
case 2: /* OS */
vmf_insert_pfn(vma, vmf->address, xive_tima_os >> PAGE_SHIFT);
return VM_FAULT_NOPAGE;
case 3: /* USER - TODO */
default:
return VM_FAULT_SIGBUS;
}
}
static const struct vm_operations_struct xive_native_tima_vmops = {
.fault = xive_native_tima_fault,
};
static int kvmppc_xive_native_mmap(struct kvm_device *dev,
struct vm_area_struct *vma)
{
KVM: PPC: Book3S HV: XIVE: Add passthrough support The KVM XICS-over-XIVE device and the proposed KVM XIVE native device implement an IRQ space for the guest using the generic IPI interrupts of the XIVE IC controller. These interrupts are allocated at the OPAL level and "mapped" into the guest IRQ number space in the range 0-0x1FFF. Interrupt management is performed in the XIVE way: using loads and stores on the addresses of the XIVE IPI interrupt ESB pages. Both KVM devices share the same internal structure caching information on the interrupts, among which the xive_irq_data struct containing the addresses of the IPI ESB pages and an extra one in case of pass-through. The later contains the addresses of the ESB pages of the underlying HW controller interrupts, PHB4 in all cases for now. A guest, when running in the XICS legacy interrupt mode, lets the KVM XICS-over-XIVE device "handle" interrupt management, that is to perform the loads and stores on the addresses of the ESB pages of the guest interrupts. However, when running in XIVE native exploitation mode, the KVM XIVE native device exposes the interrupt ESB pages to the guest and lets the guest perform directly the loads and stores. The VMA exposing the ESB pages make use of a custom VM fault handler which role is to populate the VMA with appropriate pages. When a fault occurs, the guest IRQ number is deduced from the offset, and the ESB pages of associated XIVE IPI interrupt are inserted in the VMA (using the internal structure caching information on the interrupts). Supporting device passthrough in the guest running in XIVE native exploitation mode adds some extra refinements because the ESB pages of a different HW controller (PHB4) need to be exposed to the guest along with the initial IPI ESB pages of the XIVE IC controller. But the overall mechanic is the same. When the device HW irqs are mapped into or unmapped from the guest IRQ number space, the passthru_irq helpers, kvmppc_xive_set_mapped() and kvmppc_xive_clr_mapped(), are called to record or clear the passthrough interrupt information and to perform the switch. The approach taken by this patch is to clear the ESB pages of the guest IRQ number being mapped and let the VM fault handler repopulate. The handler will insert the ESB page corresponding to the HW interrupt of the device being passed-through or the initial IPI ESB page if the device is being removed. Signed-off-by: Cédric Le Goater <clg@kaod.org> Reviewed-by: David Gibson <david@gibson.dropbear.id.au> Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2019-04-18 04:39:39 -06:00
struct kvmppc_xive *xive = dev->private;
/* We only allow mappings at fixed offset for now */
if (vma->vm_pgoff == KVM_XIVE_TIMA_PAGE_OFFSET) {
if (vma_pages(vma) > 4)
return -EINVAL;
vma->vm_ops = &xive_native_tima_vmops;
} else if (vma->vm_pgoff == KVM_XIVE_ESB_PAGE_OFFSET) {
if (vma_pages(vma) > KVMPPC_XIVE_NR_IRQS * 2)
return -EINVAL;
vma->vm_ops = &xive_native_esb_vmops;
} else {
return -EINVAL;
}
vma->vm_flags |= VM_IO | VM_PFNMAP;
vma->vm_page_prot = pgprot_noncached_wc(vma->vm_page_prot);
KVM: PPC: Book3S HV: XIVE: Add passthrough support The KVM XICS-over-XIVE device and the proposed KVM XIVE native device implement an IRQ space for the guest using the generic IPI interrupts of the XIVE IC controller. These interrupts are allocated at the OPAL level and "mapped" into the guest IRQ number space in the range 0-0x1FFF. Interrupt management is performed in the XIVE way: using loads and stores on the addresses of the XIVE IPI interrupt ESB pages. Both KVM devices share the same internal structure caching information on the interrupts, among which the xive_irq_data struct containing the addresses of the IPI ESB pages and an extra one in case of pass-through. The later contains the addresses of the ESB pages of the underlying HW controller interrupts, PHB4 in all cases for now. A guest, when running in the XICS legacy interrupt mode, lets the KVM XICS-over-XIVE device "handle" interrupt management, that is to perform the loads and stores on the addresses of the ESB pages of the guest interrupts. However, when running in XIVE native exploitation mode, the KVM XIVE native device exposes the interrupt ESB pages to the guest and lets the guest perform directly the loads and stores. The VMA exposing the ESB pages make use of a custom VM fault handler which role is to populate the VMA with appropriate pages. When a fault occurs, the guest IRQ number is deduced from the offset, and the ESB pages of associated XIVE IPI interrupt are inserted in the VMA (using the internal structure caching information on the interrupts). Supporting device passthrough in the guest running in XIVE native exploitation mode adds some extra refinements because the ESB pages of a different HW controller (PHB4) need to be exposed to the guest along with the initial IPI ESB pages of the XIVE IC controller. But the overall mechanic is the same. When the device HW irqs are mapped into or unmapped from the guest IRQ number space, the passthru_irq helpers, kvmppc_xive_set_mapped() and kvmppc_xive_clr_mapped(), are called to record or clear the passthrough interrupt information and to perform the switch. The approach taken by this patch is to clear the ESB pages of the guest IRQ number being mapped and let the VM fault handler repopulate. The handler will insert the ESB page corresponding to the HW interrupt of the device being passed-through or the initial IPI ESB page if the device is being removed. Signed-off-by: Cédric Le Goater <clg@kaod.org> Reviewed-by: David Gibson <david@gibson.dropbear.id.au> Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2019-04-18 04:39:39 -06:00
/*
* Grab the KVM device file address_space to be able to clear
* the ESB pages mapping when a device is passed-through into
* the guest.
*/
xive->mapping = vma->vm_file->f_mapping;
return 0;
}
static int kvmppc_xive_native_set_source(struct kvmppc_xive *xive, long irq,
u64 addr)
{
struct kvmppc_xive_src_block *sb;
struct kvmppc_xive_irq_state *state;
u64 __user *ubufp = (u64 __user *) addr;
u64 val;
u16 idx;
int rc;
pr_devel("%s irq=0x%lx\n", __func__, irq);
if (irq < KVMPPC_XIVE_FIRST_IRQ || irq >= KVMPPC_XIVE_NR_IRQS)
return -E2BIG;
sb = kvmppc_xive_find_source(xive, irq, &idx);
if (!sb) {
pr_debug("No source, creating source block...\n");
sb = kvmppc_xive_create_src_block(xive, irq);
if (!sb) {
pr_err("Failed to create block...\n");
return -ENOMEM;
}
}
state = &sb->irq_state[idx];
if (get_user(val, ubufp)) {
pr_err("fault getting user info !\n");
return -EFAULT;
}
arch_spin_lock(&sb->lock);
/*
* If the source doesn't already have an IPI, allocate
* one and get the corresponding data
*/
if (!state->ipi_number) {
state->ipi_number = xive_native_alloc_irq();
if (state->ipi_number == 0) {
pr_err("Failed to allocate IRQ !\n");
rc = -ENXIO;
goto unlock;
}
xive_native_populate_irq_data(state->ipi_number,
&state->ipi_data);
pr_debug("%s allocated hw_irq=0x%x for irq=0x%lx\n", __func__,
state->ipi_number, irq);
}
/* Restore LSI state */
if (val & KVM_XIVE_LEVEL_SENSITIVE) {
state->lsi = true;
if (val & KVM_XIVE_LEVEL_ASSERTED)
state->asserted = true;
pr_devel(" LSI ! Asserted=%d\n", state->asserted);
}
/* Mask IRQ to start with */
state->act_server = 0;
state->act_priority = MASKED;
xive_vm_esb_load(&state->ipi_data, XIVE_ESB_SET_PQ_01);
xive_native_configure_irq(state->ipi_number, 0, MASKED, 0);
/* Increment the number of valid sources and mark this one valid */
if (!state->valid)
xive->src_count++;
state->valid = true;
rc = 0;
unlock:
arch_spin_unlock(&sb->lock);
return rc;
}
static int kvmppc_xive_native_update_source_config(struct kvmppc_xive *xive,
struct kvmppc_xive_src_block *sb,
struct kvmppc_xive_irq_state *state,
u32 server, u8 priority, bool masked,
u32 eisn)
{
struct kvm *kvm = xive->kvm;
u32 hw_num;
int rc = 0;
arch_spin_lock(&sb->lock);
if (state->act_server == server && state->act_priority == priority &&
state->eisn == eisn)
goto unlock;
pr_devel("new_act_prio=%d new_act_server=%d mask=%d act_server=%d act_prio=%d\n",
priority, server, masked, state->act_server,
state->act_priority);
kvmppc_xive_select_irq(state, &hw_num, NULL);
if (priority != MASKED && !masked) {
rc = kvmppc_xive_select_target(kvm, &server, priority);
if (rc)
goto unlock;
state->act_priority = priority;
state->act_server = server;
state->eisn = eisn;
rc = xive_native_configure_irq(hw_num,
kvmppc_xive_vp(xive, server),
priority, eisn);
} else {
state->act_priority = MASKED;
state->act_server = 0;
state->eisn = 0;
rc = xive_native_configure_irq(hw_num, 0, MASKED, 0);
}
unlock:
arch_spin_unlock(&sb->lock);
return rc;
}
static int kvmppc_xive_native_set_source_config(struct kvmppc_xive *xive,
long irq, u64 addr)
{
struct kvmppc_xive_src_block *sb;
struct kvmppc_xive_irq_state *state;
u64 __user *ubufp = (u64 __user *) addr;
u16 src;
u64 kvm_cfg;
u32 server;
u8 priority;
bool masked;
u32 eisn;
sb = kvmppc_xive_find_source(xive, irq, &src);
if (!sb)
return -ENOENT;
state = &sb->irq_state[src];
if (!state->valid)
return -EINVAL;
if (get_user(kvm_cfg, ubufp))
return -EFAULT;
pr_devel("%s irq=0x%lx cfg=%016llx\n", __func__, irq, kvm_cfg);
priority = (kvm_cfg & KVM_XIVE_SOURCE_PRIORITY_MASK) >>
KVM_XIVE_SOURCE_PRIORITY_SHIFT;
server = (kvm_cfg & KVM_XIVE_SOURCE_SERVER_MASK) >>
KVM_XIVE_SOURCE_SERVER_SHIFT;
masked = (kvm_cfg & KVM_XIVE_SOURCE_MASKED_MASK) >>
KVM_XIVE_SOURCE_MASKED_SHIFT;
eisn = (kvm_cfg & KVM_XIVE_SOURCE_EISN_MASK) >>
KVM_XIVE_SOURCE_EISN_SHIFT;
if (priority != xive_prio_from_guest(priority)) {
pr_err("invalid priority for queue %d for VCPU %d\n",
priority, server);
return -EINVAL;
}
return kvmppc_xive_native_update_source_config(xive, sb, state, server,
priority, masked, eisn);
}
static int kvmppc_xive_native_sync_source(struct kvmppc_xive *xive,
long irq, u64 addr)
{
struct kvmppc_xive_src_block *sb;
struct kvmppc_xive_irq_state *state;
struct xive_irq_data *xd;
u32 hw_num;
u16 src;
int rc = 0;
pr_devel("%s irq=0x%lx", __func__, irq);
sb = kvmppc_xive_find_source(xive, irq, &src);
if (!sb)
return -ENOENT;
state = &sb->irq_state[src];
rc = -EINVAL;
arch_spin_lock(&sb->lock);
if (state->valid) {
kvmppc_xive_select_irq(state, &hw_num, &xd);
xive_native_sync_source(hw_num);
rc = 0;
}
arch_spin_unlock(&sb->lock);
return rc;
}
static int xive_native_validate_queue_size(u32 qshift)
{
/*
* We only support 64K pages for the moment. This is also
* advertised in the DT property "ibm,xive-eq-sizes"
*/
switch (qshift) {
case 0: /* EQ reset */
case 16:
return 0;
case 12:
case 21:
case 24:
default:
return -EINVAL;
}
}
static int kvmppc_xive_native_set_queue_config(struct kvmppc_xive *xive,
long eq_idx, u64 addr)
{
struct kvm *kvm = xive->kvm;
struct kvm_vcpu *vcpu;
struct kvmppc_xive_vcpu *xc;
void __user *ubufp = (void __user *) addr;
u32 server;
u8 priority;
struct kvm_ppc_xive_eq kvm_eq;
int rc;
__be32 *qaddr = 0;
struct page *page;
struct xive_q *q;
gfn_t gfn;
unsigned long page_size;
/*
* Demangle priority/server tuple from the EQ identifier
*/
priority = (eq_idx & KVM_XIVE_EQ_PRIORITY_MASK) >>
KVM_XIVE_EQ_PRIORITY_SHIFT;
server = (eq_idx & KVM_XIVE_EQ_SERVER_MASK) >>
KVM_XIVE_EQ_SERVER_SHIFT;
if (copy_from_user(&kvm_eq, ubufp, sizeof(kvm_eq)))
return -EFAULT;
vcpu = kvmppc_xive_find_server(kvm, server);
if (!vcpu) {
pr_err("Can't find server %d\n", server);
return -ENOENT;
}
xc = vcpu->arch.xive_vcpu;
if (priority != xive_prio_from_guest(priority)) {
pr_err("Trying to restore invalid queue %d for VCPU %d\n",
priority, server);
return -EINVAL;
}
q = &xc->queues[priority];
pr_devel("%s VCPU %d priority %d fl:%x shift:%d addr:%llx g:%d idx:%d\n",
__func__, server, priority, kvm_eq.flags,
kvm_eq.qshift, kvm_eq.qaddr, kvm_eq.qtoggle, kvm_eq.qindex);
/*
* sPAPR specifies a "Unconditional Notify (n) flag" for the
* H_INT_SET_QUEUE_CONFIG hcall which forces notification
* without using the coalescing mechanisms provided by the
* XIVE END ESBs. This is required on KVM as notification
* using the END ESBs is not supported.
*/
if (kvm_eq.flags != KVM_XIVE_EQ_ALWAYS_NOTIFY) {
pr_err("invalid flags %d\n", kvm_eq.flags);
return -EINVAL;
}
rc = xive_native_validate_queue_size(kvm_eq.qshift);
if (rc) {
pr_err("invalid queue size %d\n", kvm_eq.qshift);
return rc;
}
/* reset queue and disable queueing */
if (!kvm_eq.qshift) {
q->guest_qaddr = 0;
q->guest_qshift = 0;
rc = xive_native_configure_queue(xc->vp_id, q, priority,
NULL, 0, true);
if (rc) {
pr_err("Failed to reset queue %d for VCPU %d: %d\n",
priority, xc->server_num, rc);
return rc;
}
if (q->qpage) {
put_page(virt_to_page(q->qpage));
q->qpage = NULL;
}
return 0;
}
if (kvm_eq.qaddr & ((1ull << kvm_eq.qshift) - 1)) {
pr_err("queue page is not aligned %llx/%llx\n", kvm_eq.qaddr,
1ull << kvm_eq.qshift);
return -EINVAL;
}
gfn = gpa_to_gfn(kvm_eq.qaddr);
page = gfn_to_page(kvm, gfn);
if (is_error_page(page)) {
pr_err("Couldn't get queue page %llx!\n", kvm_eq.qaddr);
return -EINVAL;
}
page_size = kvm_host_page_size(kvm, gfn);
if (1ull << kvm_eq.qshift > page_size) {
pr_warn("Incompatible host page size %lx!\n", page_size);
return -EINVAL;
}
qaddr = page_to_virt(page) + (kvm_eq.qaddr & ~PAGE_MASK);
/*
* Backup the queue page guest address to the mark EQ page
* dirty for migration.
*/
q->guest_qaddr = kvm_eq.qaddr;
q->guest_qshift = kvm_eq.qshift;
/*
* Unconditional Notification is forced by default at the
* OPAL level because the use of END ESBs is not supported by
* Linux.
*/
rc = xive_native_configure_queue(xc->vp_id, q, priority,
(__be32 *) qaddr, kvm_eq.qshift, true);
if (rc) {
pr_err("Failed to configure queue %d for VCPU %d: %d\n",
priority, xc->server_num, rc);
put_page(page);
return rc;
}
/*
* Only restore the queue state when needed. When doing the
* H_INT_SET_SOURCE_CONFIG hcall, it should not.
*/
if (kvm_eq.qtoggle != 1 || kvm_eq.qindex != 0) {
rc = xive_native_set_queue_state(xc->vp_id, priority,
kvm_eq.qtoggle,
kvm_eq.qindex);
if (rc)
goto error;
}
rc = kvmppc_xive_attach_escalation(vcpu, priority,
xive->single_escalation);
error:
if (rc)
kvmppc_xive_native_cleanup_queue(vcpu, priority);
return rc;
}
static int kvmppc_xive_native_get_queue_config(struct kvmppc_xive *xive,
long eq_idx, u64 addr)
{
struct kvm *kvm = xive->kvm;
struct kvm_vcpu *vcpu;
struct kvmppc_xive_vcpu *xc;
struct xive_q *q;
void __user *ubufp = (u64 __user *) addr;
u32 server;
u8 priority;
struct kvm_ppc_xive_eq kvm_eq;
u64 qaddr;
u64 qshift;
u64 qeoi_page;
u32 escalate_irq;
u64 qflags;
int rc;
/*
* Demangle priority/server tuple from the EQ identifier
*/
priority = (eq_idx & KVM_XIVE_EQ_PRIORITY_MASK) >>
KVM_XIVE_EQ_PRIORITY_SHIFT;
server = (eq_idx & KVM_XIVE_EQ_SERVER_MASK) >>
KVM_XIVE_EQ_SERVER_SHIFT;
vcpu = kvmppc_xive_find_server(kvm, server);
if (!vcpu) {
pr_err("Can't find server %d\n", server);
return -ENOENT;
}
xc = vcpu->arch.xive_vcpu;
if (priority != xive_prio_from_guest(priority)) {
pr_err("invalid priority for queue %d for VCPU %d\n",
priority, server);
return -EINVAL;
}
q = &xc->queues[priority];
memset(&kvm_eq, 0, sizeof(kvm_eq));
if (!q->qpage)
return 0;
rc = xive_native_get_queue_info(xc->vp_id, priority, &qaddr, &qshift,
&qeoi_page, &escalate_irq, &qflags);
if (rc)
return rc;
kvm_eq.flags = 0;
if (qflags & OPAL_XIVE_EQ_ALWAYS_NOTIFY)
kvm_eq.flags |= KVM_XIVE_EQ_ALWAYS_NOTIFY;
kvm_eq.qshift = q->guest_qshift;
kvm_eq.qaddr = q->guest_qaddr;
rc = xive_native_get_queue_state(xc->vp_id, priority, &kvm_eq.qtoggle,
&kvm_eq.qindex);
if (rc)
return rc;
pr_devel("%s VCPU %d priority %d fl:%x shift:%d addr:%llx g:%d idx:%d\n",
__func__, server, priority, kvm_eq.flags,
kvm_eq.qshift, kvm_eq.qaddr, kvm_eq.qtoggle, kvm_eq.qindex);
if (copy_to_user(ubufp, &kvm_eq, sizeof(kvm_eq)))
return -EFAULT;
return 0;
}
static void kvmppc_xive_reset_sources(struct kvmppc_xive_src_block *sb)
{
int i;
for (i = 0; i < KVMPPC_XICS_IRQ_PER_ICS; i++) {
struct kvmppc_xive_irq_state *state = &sb->irq_state[i];
if (!state->valid)
continue;
if (state->act_priority == MASKED)
continue;
state->eisn = 0;
state->act_server = 0;
state->act_priority = MASKED;
xive_vm_esb_load(&state->ipi_data, XIVE_ESB_SET_PQ_01);
xive_native_configure_irq(state->ipi_number, 0, MASKED, 0);
if (state->pt_number) {
xive_vm_esb_load(state->pt_data, XIVE_ESB_SET_PQ_01);
xive_native_configure_irq(state->pt_number,
0, MASKED, 0);
}
}
}
static int kvmppc_xive_reset(struct kvmppc_xive *xive)
{
struct kvm *kvm = xive->kvm;
struct kvm_vcpu *vcpu;
unsigned int i;
pr_devel("%s\n", __func__);
mutex_lock(&kvm->lock);
kvm_for_each_vcpu(i, vcpu, kvm) {
struct kvmppc_xive_vcpu *xc = vcpu->arch.xive_vcpu;
unsigned int prio;
if (!xc)
continue;
kvmppc_xive_disable_vcpu_interrupts(vcpu);
for (prio = 0; prio < KVMPPC_XIVE_Q_COUNT; prio++) {
/* Single escalation, no queue 7 */
if (prio == 7 && xive->single_escalation)
break;
if (xc->esc_virq[prio]) {
free_irq(xc->esc_virq[prio], vcpu);
irq_dispose_mapping(xc->esc_virq[prio]);
kfree(xc->esc_virq_names[prio]);
xc->esc_virq[prio] = 0;
}
kvmppc_xive_native_cleanup_queue(vcpu, prio);
}
}
for (i = 0; i <= xive->max_sbid; i++) {
struct kvmppc_xive_src_block *sb = xive->src_blocks[i];
if (sb) {
arch_spin_lock(&sb->lock);
kvmppc_xive_reset_sources(sb);
arch_spin_unlock(&sb->lock);
}
}
mutex_unlock(&kvm->lock);
return 0;
}
static void kvmppc_xive_native_sync_sources(struct kvmppc_xive_src_block *sb)
{
int j;
for (j = 0; j < KVMPPC_XICS_IRQ_PER_ICS; j++) {
struct kvmppc_xive_irq_state *state = &sb->irq_state[j];
struct xive_irq_data *xd;
u32 hw_num;
if (!state->valid)
continue;
/*
* The struct kvmppc_xive_irq_state reflects the state
* of the EAS configuration and not the state of the
* source. The source is masked setting the PQ bits to
* '-Q', which is what is being done before calling
* the KVM_DEV_XIVE_EQ_SYNC control.
*
* If a source EAS is configured, OPAL syncs the XIVE
* IC of the source and the XIVE IC of the previous
* target if any.
*
* So it should be fine ignoring MASKED sources as
* they have been synced already.
*/
if (state->act_priority == MASKED)
continue;
kvmppc_xive_select_irq(state, &hw_num, &xd);
xive_native_sync_source(hw_num);
xive_native_sync_queue(hw_num);
}
}
static int kvmppc_xive_native_vcpu_eq_sync(struct kvm_vcpu *vcpu)
{
struct kvmppc_xive_vcpu *xc = vcpu->arch.xive_vcpu;
unsigned int prio;
if (!xc)
return -ENOENT;
for (prio = 0; prio < KVMPPC_XIVE_Q_COUNT; prio++) {
struct xive_q *q = &xc->queues[prio];
if (!q->qpage)
continue;
/* Mark EQ page dirty for migration */
mark_page_dirty(vcpu->kvm, gpa_to_gfn(q->guest_qaddr));
}
return 0;
}
static int kvmppc_xive_native_eq_sync(struct kvmppc_xive *xive)
{
struct kvm *kvm = xive->kvm;
struct kvm_vcpu *vcpu;
unsigned int i;
pr_devel("%s\n", __func__);
mutex_lock(&kvm->lock);
for (i = 0; i <= xive->max_sbid; i++) {
struct kvmppc_xive_src_block *sb = xive->src_blocks[i];
if (sb) {
arch_spin_lock(&sb->lock);
kvmppc_xive_native_sync_sources(sb);
arch_spin_unlock(&sb->lock);
}
}
kvm_for_each_vcpu(i, vcpu, kvm) {
kvmppc_xive_native_vcpu_eq_sync(vcpu);
}
mutex_unlock(&kvm->lock);
return 0;
}
static int kvmppc_xive_native_set_attr(struct kvm_device *dev,
struct kvm_device_attr *attr)
{
struct kvmppc_xive *xive = dev->private;
switch (attr->group) {
case KVM_DEV_XIVE_GRP_CTRL:
switch (attr->attr) {
case KVM_DEV_XIVE_RESET:
return kvmppc_xive_reset(xive);
case KVM_DEV_XIVE_EQ_SYNC:
return kvmppc_xive_native_eq_sync(xive);
}
break;
case KVM_DEV_XIVE_GRP_SOURCE:
return kvmppc_xive_native_set_source(xive, attr->attr,
attr->addr);
case KVM_DEV_XIVE_GRP_SOURCE_CONFIG:
return kvmppc_xive_native_set_source_config(xive, attr->attr,
attr->addr);
case KVM_DEV_XIVE_GRP_EQ_CONFIG:
return kvmppc_xive_native_set_queue_config(xive, attr->attr,
attr->addr);
case KVM_DEV_XIVE_GRP_SOURCE_SYNC:
return kvmppc_xive_native_sync_source(xive, attr->attr,
attr->addr);
}
return -ENXIO;
}
static int kvmppc_xive_native_get_attr(struct kvm_device *dev,
struct kvm_device_attr *attr)
{
struct kvmppc_xive *xive = dev->private;
switch (attr->group) {
case KVM_DEV_XIVE_GRP_EQ_CONFIG:
return kvmppc_xive_native_get_queue_config(xive, attr->attr,
attr->addr);
}
return -ENXIO;
}
static int kvmppc_xive_native_has_attr(struct kvm_device *dev,
struct kvm_device_attr *attr)
{
switch (attr->group) {
case KVM_DEV_XIVE_GRP_CTRL:
switch (attr->attr) {
case KVM_DEV_XIVE_RESET:
case KVM_DEV_XIVE_EQ_SYNC:
return 0;
}
break;
case KVM_DEV_XIVE_GRP_SOURCE:
case KVM_DEV_XIVE_GRP_SOURCE_CONFIG:
case KVM_DEV_XIVE_GRP_SOURCE_SYNC:
if (attr->attr >= KVMPPC_XIVE_FIRST_IRQ &&
attr->attr < KVMPPC_XIVE_NR_IRQS)
return 0;
break;
case KVM_DEV_XIVE_GRP_EQ_CONFIG:
return 0;
}
return -ENXIO;
}
/*
* Called when device fd is closed
*/
static void kvmppc_xive_native_release(struct kvm_device *dev)
{
struct kvmppc_xive *xive = dev->private;
struct kvm *kvm = xive->kvm;
struct kvm_vcpu *vcpu;
int i;
KVM: PPC: Book3S HV: XIVE: Prevent races when releasing device Now that we have the possibility of a XIVE or XICS-on-XIVE device being released while the VM is still running, we need to be careful about races and potential use-after-free bugs. Although the kvmppc_xive struct is not freed, but kept around for re-use, the kvmppc_xive_vcpu structs are freed, and they are used extensively in both the XIVE native and XICS-on-XIVE code. There are various ways in which XIVE code gets invoked: - VCPU entry and exit, which do push and pull operations on the XIVE hardware - one_reg get and set functions (vcpu->mutex is held) - XICS hypercalls (but only inside guest execution, not from kvmppc_pseries_do_hcall) - device creation calls (kvm->lock is held) - device callbacks - get/set attribute, mmap, pagefault, release/destroy - set_mapped/clr_mapped calls (kvm->lock is held) - connect_vcpu calls - debugfs file read callbacks Inside a device release function, we know that userspace cannot have an open file descriptor referring to the device, nor can it have any mmapped regions from the device. Therefore the device callbacks are excluded, as are the connect_vcpu calls (since they need a fd for the device). Further, since the caller holds the kvm->lock mutex, no other device creation calls or set/clr_mapped calls can be executing concurrently. To exclude VCPU execution and XICS hypercalls, we temporarily set kvm->arch.mmu_ready to 0. This forces any VCPU task that is trying to enter the guest to take the kvm->lock mutex, which is held by the caller of the release function. Then, sending an IPI to all other CPUs forces any VCPU currently executing in the guest to exit. Finally, we take the vcpu->mutex for each VCPU around the process of cleaning up and freeing its XIVE data structures, in order to exclude any one_reg get/set calls. To exclude the debugfs read callbacks, we just need to ensure that debugfs_remove is called before freeing any data structures. Once it returns we know that no CPU can be executing the callbacks (for our kvmppc_xive instance). Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2019-04-28 19:24:03 -06:00
int was_ready;
debugfs_remove(xive->dentry);
pr_devel("Releasing xive native device\n");
/*
KVM: PPC: Book3S HV: XIVE: Prevent races when releasing device Now that we have the possibility of a XIVE or XICS-on-XIVE device being released while the VM is still running, we need to be careful about races and potential use-after-free bugs. Although the kvmppc_xive struct is not freed, but kept around for re-use, the kvmppc_xive_vcpu structs are freed, and they are used extensively in both the XIVE native and XICS-on-XIVE code. There are various ways in which XIVE code gets invoked: - VCPU entry and exit, which do push and pull operations on the XIVE hardware - one_reg get and set functions (vcpu->mutex is held) - XICS hypercalls (but only inside guest execution, not from kvmppc_pseries_do_hcall) - device creation calls (kvm->lock is held) - device callbacks - get/set attribute, mmap, pagefault, release/destroy - set_mapped/clr_mapped calls (kvm->lock is held) - connect_vcpu calls - debugfs file read callbacks Inside a device release function, we know that userspace cannot have an open file descriptor referring to the device, nor can it have any mmapped regions from the device. Therefore the device callbacks are excluded, as are the connect_vcpu calls (since they need a fd for the device). Further, since the caller holds the kvm->lock mutex, no other device creation calls or set/clr_mapped calls can be executing concurrently. To exclude VCPU execution and XICS hypercalls, we temporarily set kvm->arch.mmu_ready to 0. This forces any VCPU task that is trying to enter the guest to take the kvm->lock mutex, which is held by the caller of the release function. Then, sending an IPI to all other CPUs forces any VCPU currently executing in the guest to exit. Finally, we take the vcpu->mutex for each VCPU around the process of cleaning up and freeing its XIVE data structures, in order to exclude any one_reg get/set calls. To exclude the debugfs read callbacks, we just need to ensure that debugfs_remove is called before freeing any data structures. Once it returns we know that no CPU can be executing the callbacks (for our kvmppc_xive instance). Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2019-04-28 19:24:03 -06:00
* Clearing mmu_ready temporarily while holding kvm->lock
* is a way of ensuring that no vcpus can enter the guest
* until we drop kvm->lock. Doing kick_all_cpus_sync()
* ensures that any vcpu executing inside the guest has
* exited the guest. Once kick_all_cpus_sync() has finished,
* we know that no vcpu can be executing the XIVE push or
* pull code or accessing the XIVE MMIO regions.
*
* Since this is the device release function, we know that
* userspace does not have any open fd or mmap referring to
* the device. Therefore there can not be any of the
* device attribute set/get, mmap, or page fault functions
* being executed concurrently, and similarly, the
* connect_vcpu and set/clr_mapped functions also cannot
* be being executed.
*/
KVM: PPC: Book3S HV: XIVE: Prevent races when releasing device Now that we have the possibility of a XIVE or XICS-on-XIVE device being released while the VM is still running, we need to be careful about races and potential use-after-free bugs. Although the kvmppc_xive struct is not freed, but kept around for re-use, the kvmppc_xive_vcpu structs are freed, and they are used extensively in both the XIVE native and XICS-on-XIVE code. There are various ways in which XIVE code gets invoked: - VCPU entry and exit, which do push and pull operations on the XIVE hardware - one_reg get and set functions (vcpu->mutex is held) - XICS hypercalls (but only inside guest execution, not from kvmppc_pseries_do_hcall) - device creation calls (kvm->lock is held) - device callbacks - get/set attribute, mmap, pagefault, release/destroy - set_mapped/clr_mapped calls (kvm->lock is held) - connect_vcpu calls - debugfs file read callbacks Inside a device release function, we know that userspace cannot have an open file descriptor referring to the device, nor can it have any mmapped regions from the device. Therefore the device callbacks are excluded, as are the connect_vcpu calls (since they need a fd for the device). Further, since the caller holds the kvm->lock mutex, no other device creation calls or set/clr_mapped calls can be executing concurrently. To exclude VCPU execution and XICS hypercalls, we temporarily set kvm->arch.mmu_ready to 0. This forces any VCPU task that is trying to enter the guest to take the kvm->lock mutex, which is held by the caller of the release function. Then, sending an IPI to all other CPUs forces any VCPU currently executing in the guest to exit. Finally, we take the vcpu->mutex for each VCPU around the process of cleaning up and freeing its XIVE data structures, in order to exclude any one_reg get/set calls. To exclude the debugfs read callbacks, we just need to ensure that debugfs_remove is called before freeing any data structures. Once it returns we know that no CPU can be executing the callbacks (for our kvmppc_xive instance). Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2019-04-28 19:24:03 -06:00
was_ready = kvm->arch.mmu_ready;
kvm->arch.mmu_ready = 0;
kick_all_cpus_sync();
/*
* We should clean up the vCPU interrupt presenters first.
*/
kvm_for_each_vcpu(i, vcpu, kvm) {
/*
* Take vcpu->mutex to ensure that no one_reg get/set ioctl
* (i.e. kvmppc_xive_native_[gs]et_vp) can be being done.
*/
mutex_lock(&vcpu->mutex);
kvmppc_xive_native_cleanup_vcpu(vcpu);
KVM: PPC: Book3S HV: XIVE: Prevent races when releasing device Now that we have the possibility of a XIVE or XICS-on-XIVE device being released while the VM is still running, we need to be careful about races and potential use-after-free bugs. Although the kvmppc_xive struct is not freed, but kept around for re-use, the kvmppc_xive_vcpu structs are freed, and they are used extensively in both the XIVE native and XICS-on-XIVE code. There are various ways in which XIVE code gets invoked: - VCPU entry and exit, which do push and pull operations on the XIVE hardware - one_reg get and set functions (vcpu->mutex is held) - XICS hypercalls (but only inside guest execution, not from kvmppc_pseries_do_hcall) - device creation calls (kvm->lock is held) - device callbacks - get/set attribute, mmap, pagefault, release/destroy - set_mapped/clr_mapped calls (kvm->lock is held) - connect_vcpu calls - debugfs file read callbacks Inside a device release function, we know that userspace cannot have an open file descriptor referring to the device, nor can it have any mmapped regions from the device. Therefore the device callbacks are excluded, as are the connect_vcpu calls (since they need a fd for the device). Further, since the caller holds the kvm->lock mutex, no other device creation calls or set/clr_mapped calls can be executing concurrently. To exclude VCPU execution and XICS hypercalls, we temporarily set kvm->arch.mmu_ready to 0. This forces any VCPU task that is trying to enter the guest to take the kvm->lock mutex, which is held by the caller of the release function. Then, sending an IPI to all other CPUs forces any VCPU currently executing in the guest to exit. Finally, we take the vcpu->mutex for each VCPU around the process of cleaning up and freeing its XIVE data structures, in order to exclude any one_reg get/set calls. To exclude the debugfs read callbacks, we just need to ensure that debugfs_remove is called before freeing any data structures. Once it returns we know that no CPU can be executing the callbacks (for our kvmppc_xive instance). Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2019-04-28 19:24:03 -06:00
mutex_unlock(&vcpu->mutex);
}
KVM: PPC: Book3S HV: XIVE: Prevent races when releasing device Now that we have the possibility of a XIVE or XICS-on-XIVE device being released while the VM is still running, we need to be careful about races and potential use-after-free bugs. Although the kvmppc_xive struct is not freed, but kept around for re-use, the kvmppc_xive_vcpu structs are freed, and they are used extensively in both the XIVE native and XICS-on-XIVE code. There are various ways in which XIVE code gets invoked: - VCPU entry and exit, which do push and pull operations on the XIVE hardware - one_reg get and set functions (vcpu->mutex is held) - XICS hypercalls (but only inside guest execution, not from kvmppc_pseries_do_hcall) - device creation calls (kvm->lock is held) - device callbacks - get/set attribute, mmap, pagefault, release/destroy - set_mapped/clr_mapped calls (kvm->lock is held) - connect_vcpu calls - debugfs file read callbacks Inside a device release function, we know that userspace cannot have an open file descriptor referring to the device, nor can it have any mmapped regions from the device. Therefore the device callbacks are excluded, as are the connect_vcpu calls (since they need a fd for the device). Further, since the caller holds the kvm->lock mutex, no other device creation calls or set/clr_mapped calls can be executing concurrently. To exclude VCPU execution and XICS hypercalls, we temporarily set kvm->arch.mmu_ready to 0. This forces any VCPU task that is trying to enter the guest to take the kvm->lock mutex, which is held by the caller of the release function. Then, sending an IPI to all other CPUs forces any VCPU currently executing in the guest to exit. Finally, we take the vcpu->mutex for each VCPU around the process of cleaning up and freeing its XIVE data structures, in order to exclude any one_reg get/set calls. To exclude the debugfs read callbacks, we just need to ensure that debugfs_remove is called before freeing any data structures. Once it returns we know that no CPU can be executing the callbacks (for our kvmppc_xive instance). Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2019-04-28 19:24:03 -06:00
kvm->arch.xive = NULL;
for (i = 0; i <= xive->max_sbid; i++) {
if (xive->src_blocks[i])
kvmppc_xive_free_sources(xive->src_blocks[i]);
kfree(xive->src_blocks[i]);
xive->src_blocks[i] = NULL;
}
if (xive->vp_base != XIVE_INVALID_VP)
xive_native_free_vp_block(xive->vp_base);
KVM: PPC: Book3S HV: XIVE: Prevent races when releasing device Now that we have the possibility of a XIVE or XICS-on-XIVE device being released while the VM is still running, we need to be careful about races and potential use-after-free bugs. Although the kvmppc_xive struct is not freed, but kept around for re-use, the kvmppc_xive_vcpu structs are freed, and they are used extensively in both the XIVE native and XICS-on-XIVE code. There are various ways in which XIVE code gets invoked: - VCPU entry and exit, which do push and pull operations on the XIVE hardware - one_reg get and set functions (vcpu->mutex is held) - XICS hypercalls (but only inside guest execution, not from kvmppc_pseries_do_hcall) - device creation calls (kvm->lock is held) - device callbacks - get/set attribute, mmap, pagefault, release/destroy - set_mapped/clr_mapped calls (kvm->lock is held) - connect_vcpu calls - debugfs file read callbacks Inside a device release function, we know that userspace cannot have an open file descriptor referring to the device, nor can it have any mmapped regions from the device. Therefore the device callbacks are excluded, as are the connect_vcpu calls (since they need a fd for the device). Further, since the caller holds the kvm->lock mutex, no other device creation calls or set/clr_mapped calls can be executing concurrently. To exclude VCPU execution and XICS hypercalls, we temporarily set kvm->arch.mmu_ready to 0. This forces any VCPU task that is trying to enter the guest to take the kvm->lock mutex, which is held by the caller of the release function. Then, sending an IPI to all other CPUs forces any VCPU currently executing in the guest to exit. Finally, we take the vcpu->mutex for each VCPU around the process of cleaning up and freeing its XIVE data structures, in order to exclude any one_reg get/set calls. To exclude the debugfs read callbacks, we just need to ensure that debugfs_remove is called before freeing any data structures. Once it returns we know that no CPU can be executing the callbacks (for our kvmppc_xive instance). Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2019-04-28 19:24:03 -06:00
kvm->arch.mmu_ready = was_ready;
/*
* A reference of the kvmppc_xive pointer is now kept under
* the xive_devices struct of the machine for reuse. It is
* freed when the VM is destroyed for now until we fix all the
* execution paths.
*/
kfree(dev);
}
KVM: PPC: Book3S HV: XIVE: Prevent races when releasing device Now that we have the possibility of a XIVE or XICS-on-XIVE device being released while the VM is still running, we need to be careful about races and potential use-after-free bugs. Although the kvmppc_xive struct is not freed, but kept around for re-use, the kvmppc_xive_vcpu structs are freed, and they are used extensively in both the XIVE native and XICS-on-XIVE code. There are various ways in which XIVE code gets invoked: - VCPU entry and exit, which do push and pull operations on the XIVE hardware - one_reg get and set functions (vcpu->mutex is held) - XICS hypercalls (but only inside guest execution, not from kvmppc_pseries_do_hcall) - device creation calls (kvm->lock is held) - device callbacks - get/set attribute, mmap, pagefault, release/destroy - set_mapped/clr_mapped calls (kvm->lock is held) - connect_vcpu calls - debugfs file read callbacks Inside a device release function, we know that userspace cannot have an open file descriptor referring to the device, nor can it have any mmapped regions from the device. Therefore the device callbacks are excluded, as are the connect_vcpu calls (since they need a fd for the device). Further, since the caller holds the kvm->lock mutex, no other device creation calls or set/clr_mapped calls can be executing concurrently. To exclude VCPU execution and XICS hypercalls, we temporarily set kvm->arch.mmu_ready to 0. This forces any VCPU task that is trying to enter the guest to take the kvm->lock mutex, which is held by the caller of the release function. Then, sending an IPI to all other CPUs forces any VCPU currently executing in the guest to exit. Finally, we take the vcpu->mutex for each VCPU around the process of cleaning up and freeing its XIVE data structures, in order to exclude any one_reg get/set calls. To exclude the debugfs read callbacks, we just need to ensure that debugfs_remove is called before freeing any data structures. Once it returns we know that no CPU can be executing the callbacks (for our kvmppc_xive instance). Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2019-04-28 19:24:03 -06:00
/*
* Create a XIVE device. kvm->lock is held.
*/
static int kvmppc_xive_native_create(struct kvm_device *dev, u32 type)
{
struct kvmppc_xive *xive;
struct kvm *kvm = dev->kvm;
int ret = 0;
pr_devel("Creating xive native device\n");
if (kvm->arch.xive)
return -EEXIST;
xive = kvmppc_xive_get_device(kvm, type);
if (!xive)
return -ENOMEM;
dev->private = xive;
xive->dev = dev;
xive->kvm = kvm;
kvm->arch.xive = xive;
KVM: PPC: Book3S HV: XIVE: Add passthrough support The KVM XICS-over-XIVE device and the proposed KVM XIVE native device implement an IRQ space for the guest using the generic IPI interrupts of the XIVE IC controller. These interrupts are allocated at the OPAL level and "mapped" into the guest IRQ number space in the range 0-0x1FFF. Interrupt management is performed in the XIVE way: using loads and stores on the addresses of the XIVE IPI interrupt ESB pages. Both KVM devices share the same internal structure caching information on the interrupts, among which the xive_irq_data struct containing the addresses of the IPI ESB pages and an extra one in case of pass-through. The later contains the addresses of the ESB pages of the underlying HW controller interrupts, PHB4 in all cases for now. A guest, when running in the XICS legacy interrupt mode, lets the KVM XICS-over-XIVE device "handle" interrupt management, that is to perform the loads and stores on the addresses of the ESB pages of the guest interrupts. However, when running in XIVE native exploitation mode, the KVM XIVE native device exposes the interrupt ESB pages to the guest and lets the guest perform directly the loads and stores. The VMA exposing the ESB pages make use of a custom VM fault handler which role is to populate the VMA with appropriate pages. When a fault occurs, the guest IRQ number is deduced from the offset, and the ESB pages of associated XIVE IPI interrupt are inserted in the VMA (using the internal structure caching information on the interrupts). Supporting device passthrough in the guest running in XIVE native exploitation mode adds some extra refinements because the ESB pages of a different HW controller (PHB4) need to be exposed to the guest along with the initial IPI ESB pages of the XIVE IC controller. But the overall mechanic is the same. When the device HW irqs are mapped into or unmapped from the guest IRQ number space, the passthru_irq helpers, kvmppc_xive_set_mapped() and kvmppc_xive_clr_mapped(), are called to record or clear the passthrough interrupt information and to perform the switch. The approach taken by this patch is to clear the ESB pages of the guest IRQ number being mapped and let the VM fault handler repopulate. The handler will insert the ESB page corresponding to the HW interrupt of the device being passed-through or the initial IPI ESB page if the device is being removed. Signed-off-by: Cédric Le Goater <clg@kaod.org> Reviewed-by: David Gibson <david@gibson.dropbear.id.au> Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2019-04-18 04:39:39 -06:00
mutex_init(&xive->mapping_lock);
/*
* Allocate a bunch of VPs. KVM_MAX_VCPUS is a large value for
* a default. Getting the max number of CPUs the VM was
* configured with would improve our usage of the XIVE VP space.
*/
xive->vp_base = xive_native_alloc_vp_block(KVM_MAX_VCPUS);
pr_devel("VP_Base=%x\n", xive->vp_base);
if (xive->vp_base == XIVE_INVALID_VP)
ret = -ENXIO;
xive->single_escalation = xive_native_has_single_escalation();
KVM: PPC: Book3S HV: XIVE: Add passthrough support The KVM XICS-over-XIVE device and the proposed KVM XIVE native device implement an IRQ space for the guest using the generic IPI interrupts of the XIVE IC controller. These interrupts are allocated at the OPAL level and "mapped" into the guest IRQ number space in the range 0-0x1FFF. Interrupt management is performed in the XIVE way: using loads and stores on the addresses of the XIVE IPI interrupt ESB pages. Both KVM devices share the same internal structure caching information on the interrupts, among which the xive_irq_data struct containing the addresses of the IPI ESB pages and an extra one in case of pass-through. The later contains the addresses of the ESB pages of the underlying HW controller interrupts, PHB4 in all cases for now. A guest, when running in the XICS legacy interrupt mode, lets the KVM XICS-over-XIVE device "handle" interrupt management, that is to perform the loads and stores on the addresses of the ESB pages of the guest interrupts. However, when running in XIVE native exploitation mode, the KVM XIVE native device exposes the interrupt ESB pages to the guest and lets the guest perform directly the loads and stores. The VMA exposing the ESB pages make use of a custom VM fault handler which role is to populate the VMA with appropriate pages. When a fault occurs, the guest IRQ number is deduced from the offset, and the ESB pages of associated XIVE IPI interrupt are inserted in the VMA (using the internal structure caching information on the interrupts). Supporting device passthrough in the guest running in XIVE native exploitation mode adds some extra refinements because the ESB pages of a different HW controller (PHB4) need to be exposed to the guest along with the initial IPI ESB pages of the XIVE IC controller. But the overall mechanic is the same. When the device HW irqs are mapped into or unmapped from the guest IRQ number space, the passthru_irq helpers, kvmppc_xive_set_mapped() and kvmppc_xive_clr_mapped(), are called to record or clear the passthrough interrupt information and to perform the switch. The approach taken by this patch is to clear the ESB pages of the guest IRQ number being mapped and let the VM fault handler repopulate. The handler will insert the ESB page corresponding to the HW interrupt of the device being passed-through or the initial IPI ESB page if the device is being removed. Signed-off-by: Cédric Le Goater <clg@kaod.org> Reviewed-by: David Gibson <david@gibson.dropbear.id.au> Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2019-04-18 04:39:39 -06:00
xive->ops = &kvmppc_xive_native_ops;
if (ret)
kfree(xive);
return ret;
}
/*
* Interrupt Pending Buffer (IPB) offset
*/
#define TM_IPB_SHIFT 40
#define TM_IPB_MASK (((u64) 0xFF) << TM_IPB_SHIFT)
int kvmppc_xive_native_get_vp(struct kvm_vcpu *vcpu, union kvmppc_one_reg *val)
{
struct kvmppc_xive_vcpu *xc = vcpu->arch.xive_vcpu;
u64 opal_state;
int rc;
if (!kvmppc_xive_enabled(vcpu))
return -EPERM;
if (!xc)
return -ENOENT;
/* Thread context registers. We only care about IPB and CPPR */
val->xive_timaval[0] = vcpu->arch.xive_saved_state.w01;
/* Get the VP state from OPAL */
rc = xive_native_get_vp_state(xc->vp_id, &opal_state);
if (rc)
return rc;
/*
* Capture the backup of IPB register in the NVT structure and
* merge it in our KVM VP state.
*/
val->xive_timaval[0] |= cpu_to_be64(opal_state & TM_IPB_MASK);
pr_devel("%s NSR=%02x CPPR=%02x IBP=%02x PIPR=%02x w01=%016llx w2=%08x opal=%016llx\n",
__func__,
vcpu->arch.xive_saved_state.nsr,
vcpu->arch.xive_saved_state.cppr,
vcpu->arch.xive_saved_state.ipb,
vcpu->arch.xive_saved_state.pipr,
vcpu->arch.xive_saved_state.w01,
(u32) vcpu->arch.xive_cam_word, opal_state);
return 0;
}
int kvmppc_xive_native_set_vp(struct kvm_vcpu *vcpu, union kvmppc_one_reg *val)
{
struct kvmppc_xive_vcpu *xc = vcpu->arch.xive_vcpu;
struct kvmppc_xive *xive = vcpu->kvm->arch.xive;
pr_devel("%s w01=%016llx vp=%016llx\n", __func__,
val->xive_timaval[0], val->xive_timaval[1]);
if (!kvmppc_xive_enabled(vcpu))
return -EPERM;
if (!xc || !xive)
return -ENOENT;
/* We can't update the state of a "pushed" VCPU */
if (WARN_ON(vcpu->arch.xive_pushed))
return -EBUSY;
/*
* Restore the thread context registers. IPB and CPPR should
* be the only ones that matter.
*/
vcpu->arch.xive_saved_state.w01 = val->xive_timaval[0];
/*
* There is no need to restore the XIVE internal state (IPB
* stored in the NVT) as the IPB register was merged in KVM VP
* state when captured.
*/
return 0;
}
static int xive_native_debug_show(struct seq_file *m, void *private)
{
struct kvmppc_xive *xive = m->private;
struct kvm *kvm = xive->kvm;
struct kvm_vcpu *vcpu;
unsigned int i;
if (!kvm)
return 0;
seq_puts(m, "=========\nVCPU state\n=========\n");
kvm_for_each_vcpu(i, vcpu, kvm) {
struct kvmppc_xive_vcpu *xc = vcpu->arch.xive_vcpu;
if (!xc)
continue;
seq_printf(m, "cpu server %#x NSR=%02x CPPR=%02x IBP=%02x PIPR=%02x w01=%016llx w2=%08x\n",
xc->server_num,
vcpu->arch.xive_saved_state.nsr,
vcpu->arch.xive_saved_state.cppr,
vcpu->arch.xive_saved_state.ipb,
vcpu->arch.xive_saved_state.pipr,
vcpu->arch.xive_saved_state.w01,
(u32) vcpu->arch.xive_cam_word);
kvmppc_xive_debug_show_queues(m, vcpu);
}
return 0;
}
static int xive_native_debug_open(struct inode *inode, struct file *file)
{
return single_open(file, xive_native_debug_show, inode->i_private);
}
static const struct file_operations xive_native_debug_fops = {
.open = xive_native_debug_open,
.read = seq_read,
.llseek = seq_lseek,
.release = single_release,
};
static void xive_native_debugfs_init(struct kvmppc_xive *xive)
{
char *name;
name = kasprintf(GFP_KERNEL, "kvm-xive-%p", xive);
if (!name) {
pr_err("%s: no memory for name\n", __func__);
return;
}
xive->dentry = debugfs_create_file(name, 0444, powerpc_debugfs_root,
xive, &xive_native_debug_fops);
pr_debug("%s: created %s\n", __func__, name);
kfree(name);
}
static void kvmppc_xive_native_init(struct kvm_device *dev)
{
struct kvmppc_xive *xive = (struct kvmppc_xive *)dev->private;
/* Register some debug interfaces */
xive_native_debugfs_init(xive);
}
struct kvm_device_ops kvm_xive_native_ops = {
.name = "kvm-xive-native",
.create = kvmppc_xive_native_create,
.init = kvmppc_xive_native_init,
.release = kvmppc_xive_native_release,
.set_attr = kvmppc_xive_native_set_attr,
.get_attr = kvmppc_xive_native_get_attr,
.has_attr = kvmppc_xive_native_has_attr,
.mmap = kvmppc_xive_native_mmap,
};
void kvmppc_xive_native_init_module(void)
{
;
}
void kvmppc_xive_native_exit_module(void)
{
;
}