On Wed, Sep 26, 2018 at 9:23 AM, Sean Christopherson
<sean.j.christopherson@xxxxxxxxx> wrote:
> Handling all VMExits due to failed consistency checks on VMEnter in
> nested_vmx_enter_non_root_mode() consolidates all relevant code into
> a single location, and removing nested_vmx_entry_failure() eliminates
> a confusing function name and label. For a VMEntry, "fail" and its
> derivatives has a very specific meaning due to the different behavior
> of a VMEnter VMFail versus VMExit, i.e. it wasn't obvious that
> nested_vmx_entry_failure() handled VMExit scenarios.
>
> Signed-off-by: Sean Christopherson <sean.j.christopherson@xxxxxxxxx>
> ---
> arch/x86/kvm/vmx.c | 75 +++++++++++++++++++++-------------------------
> 1 file changed, 34 insertions(+), 41 deletions(-)
>
> diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
> index 9fac37294f02..4188720758f8 100644
> --- a/arch/x86/kvm/vmx.c
> +++ b/arch/x86/kvm/vmx.c
> @@ -2056,9 +2056,6 @@ static inline bool is_nmi(u32 intr_info)
> static void nested_vmx_vmexit(struct kvm_vcpu *vcpu, u32 exit_reason,
> u32 exit_intr_info,
> unsigned long exit_qualification);
> -static void nested_vmx_entry_failure(struct kvm_vcpu *vcpu,
> - struct vmcs12 *vmcs12,
> - u32 reason, unsigned long qualification);
>
> static int __find_msr_index(struct vcpu_vmx *vmx, u32 msr)
> {
> @@ -12550,20 +12547,22 @@ static int check_vmentry_postreqs(struct kvm_vcpu *vcpu, struct vmcs12 *vmcs12,
> return 0;
> }
>
> +static void load_vmcs12_host_state(struct kvm_vcpu *vcpu,
> + struct vmcs12 *vmcs12);
> /*
> * If exit_qual is NULL, this is being called from state restore (either RSM
> * or KVM_SET_NESTED_STATE). Otherwise it's called from vmlaunch/vmresume.
> */
> -static int nested_vmx_enter_non_root_mode(struct kvm_vcpu *vcpu, u32 *exit_qual)
> +static int nested_vmx_enter_non_root_mode(struct kvm_vcpu *vcpu,
> + bool from_vmentry)
> {
> struct vcpu_vmx *vmx = to_vmx(vcpu);
> struct vmcs12 *vmcs12 = get_vmcs12(vcpu);
> - bool from_vmentry = !!exit_qual;
> - u32 dummy_exit_qual;
> - int r = 0;
> + u32 exit_reason = EXIT_REASON_INVALID_STATE;
> + u32 exit_qual;
>
> - if (from_vmentry && check_vmentry_postreqs(vcpu, vmcs12, exit_qual))
> - return EXIT_REASON_INVALID_STATE;
> + if (from_vmentry && check_vmentry_postreqs(vcpu, vmcs12, &exit_qual))
> + goto vmentry_fail_vmexit;
>
> enter_guest_mode(vcpu);
>
> @@ -12575,18 +12574,17 @@ static int nested_vmx_enter_non_root_mode(struct kvm_vcpu *vcpu, u32 *exit_qual)
> if (vmcs12->cpu_based_vm_exec_control & CPU_BASED_USE_TSC_OFFSETING)
> vcpu->arch.tsc_offset += vmcs12->tsc_offset;
> - r = EXIT_REASON_INVALID_STATE;
> - if (prepare_vmcs02(vcpu, vmcs12, from_vmentry ? exit_qual : &dummy_exit_qual))
> + if (prepare_vmcs02(vcpu, vmcs12, &exit_qual))
> goto fail;
>
> if (from_vmentry) {
> nested_get_vmcs12_pages(vcpu);
>
> - r = EXIT_REASON_MSR_LOAD_FAIL;
> - *exit_qual = nested_vmx_load_msr(vcpu,
> - vmcs12->vm_entry_msr_load_addr,
> - vmcs12->vm_entry_msr_load_count);
> - if (*exit_qual)
> + exit_reason = EXIT_REASON_MSR_LOAD_FAIL;
> + exit_qual = nested_vmx_load_msr(vcpu,
> + vmcs12->vm_entry_msr_load_addr,
> + vmcs12->vm_entry_msr_load_count);
> + if (exit_qual)
> goto fail;
> } else {
> /*
> @@ -12607,12 +12605,28 @@ static int nested_vmx_enter_non_root_mode(struct kvm_vcpu *vcpu, u32 *exit_qual)
> */
> return 0;
>
> + /*
> + * A failed consistency check that leads to a VMExit during L1's
> + * VMEnter to L2 is a variation of a normal VMexit, as explained in
> + * 23.7 "VM-entry failures during or after loading guest state".
> + */
I know that you just moved this comment, but as of revision
325384-067US, this is section 26.7. I try to avoid referencing SDM
section numbers, because they change quite frequently.
Reviewed-by: Jim Mattson <jmattson@xxxxxxxxxx>
