diff options
author | Liran Alon <liran.alon@oracle.com> | 2018-06-23 02:35:08 +0300 |
---|---|---|
committer | Paolo Bonzini <pbonzini@redhat.com> | 2018-08-06 17:58:42 +0200 |
commit | 61ada7488ffdef0c0f83da14a12629870abb9e97 (patch) | |
tree | ccdbf79100d02cff102cedecf749c4487ea0983e /arch/x86 | |
parent | f145d90d97bab0e11b78da1739e5db742575037c (diff) |
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>
Diffstat (limited to 'arch/x86')
-rw-r--r-- | arch/x86/kvm/vmx.c | 74 |
1 files changed, 74 insertions, 0 deletions
diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c index f8ad42bcfc2d..2a005f519032 100644 --- a/arch/x86/kvm/vmx.c +++ b/arch/x86/kvm/vmx.c @@ -645,6 +645,12 @@ struct nested_vmx { */ 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) { @@ -11996,6 +12047,18 @@ static int nested_vmx_run(struct kvm_vcpu *vcpu, bool launch) } /* + * 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); |