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KVM: nVMX: Cache shadow vmcs12 on VMEntry and flush to memory on VMExit 

This is done is done as a preparation to VMCS shadowing emulation.

Signed-off-by: Liran Alon <liran.alon@oracle.com>
Signed-off-by: Jim Mattson <jmattson@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
hifive-unleashed-5.1
Liran Alon 2018-06-23 02:35:08 +03:00 committed by Paolo Bonzini
parent f145d90d97
commit 61ada7488f
1 changed files with 74 additions and 0 deletions
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74
arch/x86/kvm/vmx.c
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@ -644,6 +644,12 @@ struct nested_vmx {
* memory during VMCLEAR and VMPTRLD.
*/
struct vmcs12 *cached_vmcs12;
/*
* Cache of the guest's shadow VMCS, existing outside of guest
* memory. Loaded from guest memory during VM entry. Flushed
* to guest memory during VM exit.
*/
struct vmcs12 *cached_shadow_vmcs12;
/*
* Indicates if the shadow vmcs must be updated with the
* data hold by vmcs12
@ -1076,6 +1082,11 @@ static inline struct vmcs12 *get_vmcs12(struct kvm_vcpu *vcpu)
return to_vmx(vcpu)->nested.cached_vmcs12;
}
static inline struct vmcs12 *get_shadow_vmcs12(struct kvm_vcpu *vcpu)
{
return to_vmx(vcpu)->nested.cached_shadow_vmcs12;
}
static bool nested_ept_ad_enabled(struct kvm_vcpu *vcpu);
static unsigned long nested_ept_get_cr3(struct kvm_vcpu *vcpu);
static u64 construct_eptp(struct kvm_vcpu *vcpu, unsigned long root_hpa);
@ -7900,6 +7911,10 @@ static int enter_vmx_operation(struct kvm_vcpu *vcpu)
if (!vmx->nested.cached_vmcs12)
goto out_cached_vmcs12;
vmx->nested.cached_shadow_vmcs12 = kmalloc(VMCS12_SIZE, GFP_KERNEL);
if (!vmx->nested.cached_shadow_vmcs12)
goto out_cached_shadow_vmcs12;
if (enable_shadow_vmcs) {
shadow_vmcs = alloc_vmcs();
if (!shadow_vmcs)
@ -7919,6 +7934,9 @@ static int enter_vmx_operation(struct kvm_vcpu *vcpu)
return 0;
out_shadow_vmcs:
kfree(vmx->nested.cached_shadow_vmcs12);
out_cached_shadow_vmcs12:
kfree(vmx->nested.cached_vmcs12);
out_cached_vmcs12:
@ -8085,6 +8103,7 @@ static void free_nested(struct vcpu_vmx *vmx)
vmx->vmcs01.shadow_vmcs = NULL;
}
kfree(vmx->nested.cached_vmcs12);
kfree(vmx->nested.cached_shadow_vmcs12);
/* Unpin physical memory we referred to in the vmcs02 */
if (vmx->nested.apic_access_page) {
kvm_release_page_dirty(vmx->nested.apic_access_page);
@ -10926,6 +10945,38 @@ static inline bool nested_vmx_prepare_msr_bitmap(struct kvm_vcpu *vcpu,
return true;
}
static void nested_cache_shadow_vmcs12(struct kvm_vcpu *vcpu,
struct vmcs12 *vmcs12)
{
struct vmcs12 *shadow;
struct page *page;
if (!nested_cpu_has_shadow_vmcs(vmcs12) ||
vmcs12->vmcs_link_pointer == -1ull)
return;
shadow = get_shadow_vmcs12(vcpu);
page = kvm_vcpu_gpa_to_page(vcpu, vmcs12->vmcs_link_pointer);
memcpy(shadow, kmap(page), VMCS12_SIZE);
kunmap(page);
kvm_release_page_clean(page);
}
static void nested_flush_cached_shadow_vmcs12(struct kvm_vcpu *vcpu,
struct vmcs12 *vmcs12)
{
struct vcpu_vmx *vmx = to_vmx(vcpu);
if (!nested_cpu_has_shadow_vmcs(vmcs12) ||
vmcs12->vmcs_link_pointer == -1ull)
return;
kvm_write_guest(vmx->vcpu.kvm, vmcs12->vmcs_link_pointer,
get_shadow_vmcs12(vcpu), VMCS12_SIZE);
}
static int nested_vmx_check_apic_access_controls(struct kvm_vcpu *vcpu,
struct vmcs12 *vmcs12)
{
@ -11995,6 +12046,18 @@ static int nested_vmx_run(struct kvm_vcpu *vcpu, bool launch)
return 1;
}
/*
* Must happen outside of enter_vmx_non_root_mode() as it will
* also be used as part of restoring nVMX state for
* snapshot restore (migration).
*
* In this flow, it is assumed that vmcs12 cache was
* trasferred as part of captured nVMX state and should
* therefore not be read from guest memory (which may not
* exist on destination host yet).
*/
nested_cache_shadow_vmcs12(vcpu, vmcs12);
/*
* If we're entering a halted L2 vcpu and the L2 vcpu won't be woken
* by event injection, halt vcpu.
@ -12504,6 +12567,17 @@ static void nested_vmx_vmexit(struct kvm_vcpu *vcpu, u32 exit_reason,
prepare_vmcs12(vcpu, vmcs12, exit_reason, exit_intr_info,
exit_qualification);
/*
* Must happen outside of sync_vmcs12() as it will
* also be used to capture vmcs12 cache as part of
* capturing nVMX state for snapshot (migration).
*
* Otherwise, this flush will dirty guest memory at a
* point it is already assumed by user-space to be
* immutable.
*/
nested_flush_cached_shadow_vmcs12(vcpu, vmcs12);
if (nested_vmx_store_msr(vcpu, vmcs12->vm_exit_msr_store_addr,
vmcs12->vm_exit_msr_store_count))
nested_vmx_abort(vcpu, VMX_ABORT_SAVE_GUEST_MSR_FAIL);