From 6beb7bd52e482c213dfa6c1c88e27a579df5bf4d Mon Sep 17 00:00:00 2001 From: Jim Mattson Date: Wed, 30 Nov 2016 12:03:45 -0800 Subject: [PATCH] kvm: nVMX: Refactor nested_get_vmcs12_pages() Perform the checks on vmcs12 state early, but defer the gpa->hpa lookups until after prepare_vmcs02. Later, when we restore the checkpointed state of a vCPU in guest mode, we will not be able to do the gpa->hpa lookups when the restore is done. Signed-off-by: Jim Mattson Signed-off-by: Paolo Bonzini --- arch/x86/kvm/vmx.c | 138 ++++++++++++++++++++++----------------------- 1 file changed, 69 insertions(+), 69 deletions(-) diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c index ef9affcabdeb..650f34336fad 100644 --- a/arch/x86/kvm/vmx.c +++ b/arch/x86/kvm/vmx.c @@ -9626,17 +9626,16 @@ static void vmx_inject_page_fault_nested(struct kvm_vcpu *vcpu, kvm_inject_page_fault(vcpu, fault); } -static bool nested_get_vmcs12_pages(struct kvm_vcpu *vcpu, +static inline bool nested_vmx_merge_msr_bitmap(struct kvm_vcpu *vcpu, + struct vmcs12 *vmcs12); + +static void nested_get_vmcs12_pages(struct kvm_vcpu *vcpu, struct vmcs12 *vmcs12) { struct vcpu_vmx *vmx = to_vmx(vcpu); - int maxphyaddr = cpuid_maxphyaddr(vcpu); + u64 hpa; if (nested_cpu_has2(vmcs12, SECONDARY_EXEC_VIRTUALIZE_APIC_ACCESSES)) { - if (!PAGE_ALIGNED(vmcs12->apic_access_addr) || - vmcs12->apic_access_addr >> maxphyaddr) - return false; - /* * Translate L1 physical address to host physical * address for vmcs02. Keep the page pinned, so this @@ -9647,59 +9646,80 @@ static bool nested_get_vmcs12_pages(struct kvm_vcpu *vcpu, nested_release_page(vmx->nested.apic_access_page); vmx->nested.apic_access_page = nested_get_page(vcpu, vmcs12->apic_access_addr); + /* + * If translation failed, no matter: This feature asks + * to exit when accessing the given address, and if it + * can never be accessed, this feature won't do + * anything anyway. + */ + if (vmx->nested.apic_access_page) { + hpa = page_to_phys(vmx->nested.apic_access_page); + vmcs_write64(APIC_ACCESS_ADDR, hpa); + } else { + vmcs_clear_bits(SECONDARY_VM_EXEC_CONTROL, + SECONDARY_EXEC_VIRTUALIZE_APIC_ACCESSES); + } + } else if (!(nested_cpu_has_virt_x2apic_mode(vmcs12)) && + cpu_need_virtualize_apic_accesses(&vmx->vcpu)) { + vmcs_set_bits(SECONDARY_VM_EXEC_CONTROL, + SECONDARY_EXEC_VIRTUALIZE_APIC_ACCESSES); + kvm_vcpu_reload_apic_access_page(vcpu); } if (nested_cpu_has(vmcs12, CPU_BASED_TPR_SHADOW)) { - if (!PAGE_ALIGNED(vmcs12->virtual_apic_page_addr) || - vmcs12->virtual_apic_page_addr >> maxphyaddr) - return false; - if (vmx->nested.virtual_apic_page) /* shouldn't happen */ nested_release_page(vmx->nested.virtual_apic_page); vmx->nested.virtual_apic_page = nested_get_page(vcpu, vmcs12->virtual_apic_page_addr); /* - * Failing the vm entry is _not_ what the processor does - * but it's basically the only possibility we have. - * We could still enter the guest if CR8 load exits are - * enabled, CR8 store exits are enabled, and virtualize APIC - * access is disabled; in this case the processor would never - * use the TPR shadow and we could simply clear the bit from - * the execution control. But such a configuration is useless, - * so let's keep the code simple. + * If translation failed, VM entry will fail because + * prepare_vmcs02 set VIRTUAL_APIC_PAGE_ADDR to -1ull. + * Failing the vm entry is _not_ what the processor + * does but it's basically the only possibility we + * have. We could still enter the guest if CR8 load + * exits are enabled, CR8 store exits are enabled, and + * virtualize APIC access is disabled; in this case + * the processor would never use the TPR shadow and we + * could simply clear the bit from the execution + * control. But such a configuration is useless, so + * let's keep the code simple. */ - if (!vmx->nested.virtual_apic_page) - return false; + if (vmx->nested.virtual_apic_page) { + hpa = page_to_phys(vmx->nested.virtual_apic_page); + vmcs_write64(VIRTUAL_APIC_PAGE_ADDR, hpa); + } } if (nested_cpu_has_posted_intr(vmcs12)) { - if (!IS_ALIGNED(vmcs12->posted_intr_desc_addr, 64) || - vmcs12->posted_intr_desc_addr >> maxphyaddr) - return false; - if (vmx->nested.pi_desc_page) { /* shouldn't happen */ kunmap(vmx->nested.pi_desc_page); nested_release_page(vmx->nested.pi_desc_page); } vmx->nested.pi_desc_page = nested_get_page(vcpu, vmcs12->posted_intr_desc_addr); - if (!vmx->nested.pi_desc_page) - return false; - vmx->nested.pi_desc = (struct pi_desc *)kmap(vmx->nested.pi_desc_page); if (!vmx->nested.pi_desc) { nested_release_page_clean(vmx->nested.pi_desc_page); - return false; + return; } vmx->nested.pi_desc = (struct pi_desc *)((void *)vmx->nested.pi_desc + (unsigned long)(vmcs12->posted_intr_desc_addr & (PAGE_SIZE - 1))); + vmcs_write64(POSTED_INTR_DESC_ADDR, + page_to_phys(vmx->nested.pi_desc_page) + + (unsigned long)(vmcs12->posted_intr_desc_addr & + (PAGE_SIZE - 1))); } - - return true; + if (cpu_has_vmx_msr_bitmap() && + nested_cpu_has(vmcs12, CPU_BASED_USE_MSR_BITMAPS) && + nested_vmx_merge_msr_bitmap(vcpu, vmcs12)) + ; + else + vmcs_clear_bits(CPU_BASED_VM_EXEC_CONTROL, + CPU_BASED_USE_MSR_BITMAPS); } static void vmx_start_preemption_timer(struct kvm_vcpu *vcpu) @@ -10146,12 +10166,9 @@ static int prepare_vmcs02(struct kvm_vcpu *vcpu, struct vmcs12 *vmcs12, vmx->nested.posted_intr_nv = vmcs12->posted_intr_nv; vmx->nested.pi_pending = false; vmcs_write16(POSTED_INTR_NV, POSTED_INTR_VECTOR); - vmcs_write64(POSTED_INTR_DESC_ADDR, - page_to_phys(vmx->nested.pi_desc_page) + - (unsigned long)(vmcs12->posted_intr_desc_addr & - (PAGE_SIZE - 1))); - } else + } else { exec_control &= ~PIN_BASED_POSTED_INTR; + } vmcs_write32(PIN_BASED_VM_EXEC_CONTROL, exec_control); @@ -10196,26 +10213,6 @@ static int prepare_vmcs02(struct kvm_vcpu *vcpu, struct vmcs12 *vmcs12, CPU_BASED_ACTIVATE_SECONDARY_CONTROLS)) exec_control |= vmcs12->secondary_vm_exec_control; - if (exec_control & SECONDARY_EXEC_VIRTUALIZE_APIC_ACCESSES) { - /* - * If translation failed, no matter: This feature asks - * to exit when accessing the given address, and if it - * can never be accessed, this feature won't do - * anything anyway. - */ - if (!vmx->nested.apic_access_page) - exec_control &= - ~SECONDARY_EXEC_VIRTUALIZE_APIC_ACCESSES; - else - vmcs_write64(APIC_ACCESS_ADDR, - page_to_phys(vmx->nested.apic_access_page)); - } else if (!(nested_cpu_has_virt_x2apic_mode(vmcs12)) && - cpu_need_virtualize_apic_accesses(&vmx->vcpu)) { - exec_control |= - SECONDARY_EXEC_VIRTUALIZE_APIC_ACCESSES; - kvm_vcpu_reload_apic_access_page(vcpu); - } - if (exec_control & SECONDARY_EXEC_VIRTUAL_INTR_DELIVERY) { vmcs_write64(EOI_EXIT_BITMAP0, vmcs12->eoi_exit_bitmap0); @@ -10230,6 +10227,15 @@ static int prepare_vmcs02(struct kvm_vcpu *vcpu, struct vmcs12 *vmcs12, } nested_ept_enabled = (exec_control & SECONDARY_EXEC_ENABLE_EPT) != 0; + + /* + * Write an illegal value to APIC_ACCESS_ADDR. Later, + * nested_get_vmcs12_pages will either fix it up or + * remove the VM execution control. + */ + if (exec_control & SECONDARY_EXEC_VIRTUALIZE_APIC_ACCESSES) + vmcs_write64(APIC_ACCESS_ADDR, -1ull); + vmcs_write32(SECONDARY_VM_EXEC_CONTROL, exec_control); } @@ -10266,19 +10272,16 @@ static int prepare_vmcs02(struct kvm_vcpu *vcpu, struct vmcs12 *vmcs12, exec_control &= ~CPU_BASED_TPR_SHADOW; exec_control |= vmcs12->cpu_based_vm_exec_control; + /* + * Write an illegal value to VIRTUAL_APIC_PAGE_ADDR. Later, if + * nested_get_vmcs12_pages can't fix it up, the illegal value + * will result in a VM entry failure. + */ if (exec_control & CPU_BASED_TPR_SHADOW) { - vmcs_write64(VIRTUAL_APIC_PAGE_ADDR, - page_to_phys(vmx->nested.virtual_apic_page)); + vmcs_write64(VIRTUAL_APIC_PAGE_ADDR, -1ull); vmcs_write32(TPR_THRESHOLD, vmcs12->tpr_threshold); } - if (cpu_has_vmx_msr_bitmap() && - exec_control & CPU_BASED_USE_MSR_BITMAPS && - nested_vmx_merge_msr_bitmap(vcpu, vmcs12)) - ; /* MSR_BITMAP will be set by following vmx_set_efer. */ - else - exec_control &= ~CPU_BASED_USE_MSR_BITMAPS; - /* * Merging of IO bitmap not currently supported. * Rather, exit every time. @@ -10456,11 +10459,6 @@ static int nested_vmx_run(struct kvm_vcpu *vcpu, bool launch) goto out; } - if (!nested_get_vmcs12_pages(vcpu, vmcs12)) { - nested_vmx_failValid(vcpu, VMXERR_ENTRY_INVALID_CONTROL_FIELD); - goto out; - } - if (nested_vmx_check_msr_bitmap_controls(vcpu, vmcs12)) { nested_vmx_failValid(vcpu, VMXERR_ENTRY_INVALID_CONTROL_FIELD); goto out; @@ -10592,6 +10590,8 @@ static int nested_vmx_run(struct kvm_vcpu *vcpu, bool launch) return 1; } + nested_get_vmcs12_pages(vcpu, vmcs12); + msr_entry_idx = nested_vmx_load_msr(vcpu, vmcs12->vm_entry_msr_load_addr, vmcs12->vm_entry_msr_load_count); -- 2.30.2