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arm64: KVM: Make VHE Stage-2 TLB invalidation operations non-interruptible 

Contrary to the non-VHE version of the TLB invalidation helpers, the VHE
code  has interrupts enabled, meaning that we can take an interrupt in
the middle of such a sequence, and start running something else with
HCR_EL2.TGE cleared.

That's really not a good idea.

Take the heavy-handed option and disable interrupts in
__tlb_switch_to_guest_vhe, restoring them in __tlb_switch_to_host_vhe.
The latter also gain an ISB in order to make sure that TGE really has
taken effect.

Cc: stable@vger.kernel.org
Acked-by: Christoffer Dall <christoffer.dall@arm.com>
Reviewed-by: James Morse <james.morse@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
hifive-unleashed-5.1
Marc Zyngier 2018-12-06 17:31:19 +00:00 committed by Will Deacon
parent 9ff01193a2
commit c987876a80
1 changed files with 25 additions and 10 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

35
arch/arm64/kvm/hyp/tlb.c
View File

@ -15,14 +15,19 @@
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#include <linux/irqflags.h>
#include <asm/kvm_hyp.h>
#include <asm/kvm_mmu.h>
#include <asm/tlbflush.h>
static void __hyp_text __tlb_switch_to_guest_vhe(struct kvm *kvm)
static void __hyp_text __tlb_switch_to_guest_vhe(struct kvm *kvm,
unsigned long *flags)
{
u64 val;
local_irq_save(*flags);
/*
* With VHE enabled, we have HCR_EL2.{E2H,TGE} = {1,1}, and
* most TLB operations target EL2/EL0. In order to affect the
@ -37,7 +42,8 @@ static void __hyp_text __tlb_switch_to_guest_vhe(struct kvm *kvm)
isb();
}
static void __hyp_text __tlb_switch_to_guest_nvhe(struct kvm *kvm)
static void __hyp_text __tlb_switch_to_guest_nvhe(struct kvm *kvm,
unsigned long *flags)
{
__load_guest_stage2(kvm);
isb();
@ -48,7 +54,8 @@ static hyp_alternate_select(__tlb_switch_to_guest,
__tlb_switch_to_guest_vhe,
ARM64_HAS_VIRT_HOST_EXTN);
static void __hyp_text __tlb_switch_to_host_vhe(struct kvm *kvm)
static void __hyp_text __tlb_switch_to_host_vhe(struct kvm *kvm,
unsigned long flags)
{
/*
* We're done with the TLB operation, let's restore the host's
@ -56,9 +63,12 @@ static void __hyp_text __tlb_switch_to_host_vhe(struct kvm *kvm)
*/
write_sysreg(0, vttbr_el2);
write_sysreg(HCR_HOST_VHE_FLAGS, hcr_el2);
isb();
local_irq_restore(flags);
}
static void __hyp_text __tlb_switch_to_host_nvhe(struct kvm *kvm)
static void __hyp_text __tlb_switch_to_host_nvhe(struct kvm *kvm,
unsigned long flags)
{
write_sysreg(0, vttbr_el2);
}
@ -70,11 +80,13 @@ static hyp_alternate_select(__tlb_switch_to_host,
void __hyp_text __kvm_tlb_flush_vmid_ipa(struct kvm *kvm, phys_addr_t ipa)
{
unsigned long flags;
dsb(ishst);
/* Switch to requested VMID */
kvm = kern_hyp_va(kvm);
__tlb_switch_to_guest()(kvm);
__tlb_switch_to_guest()(kvm, &flags);
/*
* We could do so much better if we had the VA as well.
@ -117,36 +129,39 @@ void __hyp_text __kvm_tlb_flush_vmid_ipa(struct kvm *kvm, phys_addr_t ipa)
if (!has_vhe() && icache_is_vpipt())
__flush_icache_all();
__tlb_switch_to_host()(kvm);
__tlb_switch_to_host()(kvm, flags);
}
void __hyp_text __kvm_tlb_flush_vmid(struct kvm *kvm)
{
unsigned long flags;
dsb(ishst);
/* Switch to requested VMID */
kvm = kern_hyp_va(kvm);
__tlb_switch_to_guest()(kvm);
__tlb_switch_to_guest()(kvm, &flags);
__tlbi(vmalls12e1is);
dsb(ish);
isb();
__tlb_switch_to_host()(kvm);
__tlb_switch_to_host()(kvm, flags);
}
void __hyp_text __kvm_tlb_flush_local_vmid(struct kvm_vcpu *vcpu)
{
struct kvm *kvm = kern_hyp_va(kern_hyp_va(vcpu)->kvm);
unsigned long flags;
/* Switch to requested VMID */
__tlb_switch_to_guest()(kvm);
__tlb_switch_to_guest()(kvm, &flags);
__tlbi(vmalle1);
dsb(nsh);
isb();
__tlb_switch_to_host()(kvm);
__tlb_switch_to_host()(kvm, flags);
}
void __hyp_text __kvm_flush_vm_context(void)