diff options
Diffstat (limited to 'arch/x86/kvm/vmx/vmx.c')
| -rw-r--r-- | arch/x86/kvm/vmx/vmx.c | 66 |
1 files changed, 56 insertions, 10 deletions
diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c index 2d9d155691a7..0ecf4be2c6af 100644 --- a/arch/x86/kvm/vmx/vmx.c +++ b/arch/x86/kvm/vmx/vmx.c @@ -3384,15 +3384,15 @@ static bool vmx_is_valid_cr4(struct kvm_vcpu *vcpu, unsigned long cr4) void vmx_set_cr4(struct kvm_vcpu *vcpu, unsigned long cr4) { - unsigned long old_cr4 = vcpu->arch.cr4; + unsigned long old_cr4 = kvm_read_cr4(vcpu); struct vcpu_vmx *vmx = to_vmx(vcpu); + unsigned long hw_cr4; + /* * Pass through host's Machine Check Enable value to hw_cr4, which * is in force while we are in guest mode. Do not let guests control * this bit, even if host CR4.MCE == 0. */ - unsigned long hw_cr4; - hw_cr4 = (cr4_read_shadow() & X86_CR4_MCE) | (cr4 & ~X86_CR4_MCE); if (is_unrestricted_guest(vcpu)) hw_cr4 |= KVM_VM_CR4_ALWAYS_ON_UNRESTRICTED_GUEST; @@ -3401,7 +3401,7 @@ void vmx_set_cr4(struct kvm_vcpu *vcpu, unsigned long cr4) else hw_cr4 |= KVM_PMODE_VM_CR4_ALWAYS_ON; - if (!boot_cpu_has(X86_FEATURE_UMIP) && vmx_umip_emulated()) { + if (vmx_umip_emulated()) { if (cr4 & X86_CR4_UMIP) { secondary_exec_controls_setbit(vmx, SECONDARY_EXEC_DESC); hw_cr4 &= ~X86_CR4_UMIP; @@ -5399,7 +5399,13 @@ static int handle_set_cr4(struct kvm_vcpu *vcpu, unsigned long val) static int handle_desc(struct kvm_vcpu *vcpu) { - WARN_ON(!(vcpu->arch.cr4 & X86_CR4_UMIP)); + /* + * UMIP emulation relies on intercepting writes to CR4.UMIP, i.e. this + * and other code needs to be updated if UMIP can be guest owned. + */ + BUILD_BUG_ON(KVM_POSSIBLE_CR4_GUEST_BITS & X86_CR4_UMIP); + + WARN_ON_ONCE(!kvm_is_cr4_bit_set(vcpu, X86_CR4_UMIP)); return kvm_emulate_instruction(vcpu, 0); } @@ -6705,7 +6711,12 @@ void vmx_set_virtual_apic_mode(struct kvm_vcpu *vcpu) static void vmx_set_apic_access_page_addr(struct kvm_vcpu *vcpu) { - struct page *page; + const gfn_t gfn = APIC_DEFAULT_PHYS_BASE >> PAGE_SHIFT; + struct kvm *kvm = vcpu->kvm; + struct kvm_memslots *slots = kvm_memslots(kvm); + struct kvm_memory_slot *slot; + unsigned long mmu_seq; + kvm_pfn_t pfn; /* Defer reload until vmcs01 is the current VMCS. */ if (is_guest_mode(vcpu)) { @@ -6717,18 +6728,53 @@ static void vmx_set_apic_access_page_addr(struct kvm_vcpu *vcpu) SECONDARY_EXEC_VIRTUALIZE_APIC_ACCESSES)) return; - page = gfn_to_page(vcpu->kvm, APIC_DEFAULT_PHYS_BASE >> PAGE_SHIFT); - if (is_error_page(page)) + /* + * Grab the memslot so that the hva lookup for the mmu_notifier retry + * is guaranteed to use the same memslot as the pfn lookup, i.e. rely + * on the pfn lookup's validation of the memslot to ensure a valid hva + * is used for the retry check. + */ + slot = id_to_memslot(slots, APIC_ACCESS_PAGE_PRIVATE_MEMSLOT); + if (!slot || slot->flags & KVM_MEMSLOT_INVALID) return; - vmcs_write64(APIC_ACCESS_ADDR, page_to_phys(page)); + /* + * Ensure that the mmu_notifier sequence count is read before KVM + * retrieves the pfn from the primary MMU. Note, the memslot is + * protected by SRCU, not the mmu_notifier. Pairs with the smp_wmb() + * in kvm_mmu_invalidate_end(). + */ + mmu_seq = kvm->mmu_invalidate_seq; + smp_rmb(); + + /* + * No need to retry if the memslot does not exist or is invalid. KVM + * controls the APIC-access page memslot, and only deletes the memslot + * if APICv is permanently inhibited, i.e. the memslot won't reappear. + */ + pfn = gfn_to_pfn_memslot(slot, gfn); + if (is_error_noslot_pfn(pfn)) + return; + + read_lock(&vcpu->kvm->mmu_lock); + if (mmu_invalidate_retry_hva(kvm, mmu_seq, + gfn_to_hva_memslot(slot, gfn))) { + kvm_make_request(KVM_REQ_APIC_PAGE_RELOAD, vcpu); + read_unlock(&vcpu->kvm->mmu_lock); + goto out; + } + + vmcs_write64(APIC_ACCESS_ADDR, pfn_to_hpa(pfn)); + read_unlock(&vcpu->kvm->mmu_lock); + vmx_flush_tlb_current(vcpu); +out: /* * Do not pin apic access page in memory, the MMU notifier * will call us again if it is migrated or swapped out. */ - put_page(page); + kvm_release_pfn_clean(pfn); } static void vmx_hwapic_isr_update(int max_isr) |