KVM: nVMX: Use '-1' in 'hv_evmcs_vmptr' to indicate that eVMCS is not in use

Instead of checking 'vmx->nested.hv_evmcs' use '-1' in
'vmx->nested.hv_evmcs_vmptr' to indicate 'evmcs is not in use' state. This
matches how we check 'vmx->nested.current_vmptr'. Introduce EVMPTR_INVALID
and evmptr_is_valid() and use it instead of raw '-1' check as a preparation
to adding other 'special' values.

No functional change intended.

Suggested-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <20210526132026.270394-2-vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

diff --git a/arch/x86/kvm/vmx/evmcs.c b/arch/x86/kvm/vmx/evmcs.c
index 41f2466..896b2a5 100644 (file)
--- a/arch/x86/kvm/vmx/evmcs.c
+++ b/arch/x86/kvm/vmx/evmcs.c
@@ -319,6 +319,9 @@ bool nested_enlightened_vmentry(struct kvm_vcpu *vcpu, u64 *evmcs_gpa)
        if (unlikely(!assist_page.enlighten_vmentry))
                return false;
 
+       if (unlikely(!evmptr_is_valid(assist_page.current_nested_vmcs)))
+               return false;
+
        *evmcs_gpa = assist_page.current_nested_vmcs;
 
        return true;

diff --git a/arch/x86/kvm/vmx/evmcs.h b/arch/x86/kvm/vmx/evmcs.h
index bd41d94..47f802f 100644 (file)
--- a/arch/x86/kvm/vmx/evmcs.h
+++ b/arch/x86/kvm/vmx/evmcs.h
@@ -197,6 +197,13 @@ static inline void evmcs_load(u64 phys_addr) {}
 static inline void evmcs_touch_msr_bitmap(void) {}
 #endif /* IS_ENABLED(CONFIG_HYPERV) */
 
+#define EVMPTR_INVALID (-1ULL)
+
+static inline bool evmptr_is_valid(u64 evmptr)
+{
+       return evmptr != EVMPTR_INVALID;
+}
+
 enum nested_evmptrld_status {
        EVMPTRLD_DISABLED,
        EVMPTRLD_SUCCEEDED,

diff --git a/arch/x86/kvm/vmx/nested.c b/arch/x86/kvm/vmx/nested.c
index 1a2f000..84d9a8d 100644 (file)
--- a/arch/x86/kvm/vmx/nested.c
+++ b/arch/x86/kvm/vmx/nested.c
@@ -187,7 +187,8 @@ static int nested_vmx_fail(struct kvm_vcpu *vcpu, u32 vm_instruction_error)
         * failValid writes the error number to the current VMCS, which
         * can't be done if there isn't a current VMCS.
         */
-       if (vmx->nested.current_vmptr == -1ull && !vmx->nested.hv_evmcs)
+       if (vmx->nested.current_vmptr == -1ull &&
+           !evmptr_is_valid(vmx->nested.hv_evmcs_vmptr))
                return nested_vmx_failInvalid(vcpu);
 
        return nested_vmx_failValid(vcpu, vm_instruction_error);
@@ -221,12 +222,12 @@ static inline void nested_release_evmcs(struct kvm_vcpu *vcpu)
 {
        struct vcpu_vmx *vmx = to_vmx(vcpu);
 
-       if (!vmx->nested.hv_evmcs)
-               return;
+       if (evmptr_is_valid(vmx->nested.hv_evmcs_vmptr)) {
+               kvm_vcpu_unmap(vcpu, &vmx->nested.hv_evmcs_map, true);
+               vmx->nested.hv_evmcs = NULL;
+       }
 
-       kvm_vcpu_unmap(vcpu, &vmx->nested.hv_evmcs_map, true);
-       vmx->nested.hv_evmcs_vmptr = 0;
-       vmx->nested.hv_evmcs = NULL;
+       vmx->nested.hv_evmcs_vmptr = EVMPTR_INVALID;
 }
 
 static void vmx_sync_vmcs_host_state(struct vcpu_vmx *vmx,
@@ -1981,10 +1982,8 @@ static enum nested_evmptrld_status nested_vmx_handle_enlightened_vmptrld(
        if (!nested_enlightened_vmentry(vcpu, &evmcs_gpa))
                return EVMPTRLD_DISABLED;
 
-       if (unlikely(!vmx->nested.hv_evmcs ||
-                    evmcs_gpa != vmx->nested.hv_evmcs_vmptr)) {
-               if (!vmx->nested.hv_evmcs)
-                       vmx->nested.current_vmptr = -1ull;
+       if (unlikely(evmcs_gpa != vmx->nested.hv_evmcs_vmptr)) {
+               vmx->nested.current_vmptr = -1ull;
 
                nested_release_evmcs(vcpu);
 
@@ -2055,7 +2054,7 @@ void nested_sync_vmcs12_to_shadow(struct kvm_vcpu *vcpu)
 {
        struct vcpu_vmx *vmx = to_vmx(vcpu);
 
-       if (vmx->nested.hv_evmcs) {
+       if (evmptr_is_valid(vmx->nested.hv_evmcs_vmptr)) {
                copy_vmcs12_to_enlightened(vmx);
                /* All fields are clean */
                vmx->nested.hv_evmcs->hv_clean_fields |=
@@ -2207,7 +2206,7 @@ static void prepare_vmcs02_early(struct vcpu_vmx *vmx, struct vmcs12 *vmcs12)
        u32 exec_control;
        u64 guest_efer = nested_vmx_calc_efer(vmx, vmcs12);
 
-       if (vmx->nested.dirty_vmcs12 || vmx->nested.hv_evmcs)
+       if (vmx->nested.dirty_vmcs12 || evmptr_is_valid(vmx->nested.hv_evmcs_vmptr))
                prepare_vmcs02_early_rare(vmx, vmcs12);
 
        /*
@@ -2492,15 +2491,14 @@ static int prepare_vmcs02(struct kvm_vcpu *vcpu, struct vmcs12 *vmcs12,
                          enum vm_entry_failure_code *entry_failure_code)
 {
        struct vcpu_vmx *vmx = to_vmx(vcpu);
-       struct hv_enlightened_vmcs *hv_evmcs = vmx->nested.hv_evmcs;
        bool load_guest_pdptrs_vmcs12 = false;
 
-       if (vmx->nested.dirty_vmcs12 || hv_evmcs) {
+       if (vmx->nested.dirty_vmcs12 || evmptr_is_valid(vmx->nested.hv_evmcs_vmptr)) {
                prepare_vmcs02_rare(vmx, vmcs12);
                vmx->nested.dirty_vmcs12 = false;
 
-               load_guest_pdptrs_vmcs12 = !hv_evmcs ||
-                       !(hv_evmcs->hv_clean_fields &
+               load_guest_pdptrs_vmcs12 = !evmptr_is_valid(vmx->nested.hv_evmcs_vmptr) ||
+                       !(vmx->nested.hv_evmcs->hv_clean_fields &
                          HV_VMX_ENLIGHTENED_CLEAN_FIELD_GUEST_GRP1);
        }
 
@@ -3102,7 +3100,8 @@ static bool nested_get_evmcs_page(struct kvm_vcpu *vcpu)
         * L2 was running), map it here to make sure vmcs12 changes are
         * properly reflected.
         */
-       if (vmx->nested.enlightened_vmcs_enabled && !vmx->nested.hv_evmcs) {
+       if (vmx->nested.enlightened_vmcs_enabled &&
+           !evmptr_is_valid(vmx->nested.hv_evmcs_vmptr)) {
                enum nested_evmptrld_status evmptrld_status =
                        nested_vmx_handle_enlightened_vmptrld(vcpu, false);
 
@@ -3465,7 +3464,7 @@ vmentry_fail_vmexit:
 
        load_vmcs12_host_state(vcpu, vmcs12);
        vmcs12->vm_exit_reason = exit_reason.full;
-       if (enable_shadow_vmcs || vmx->nested.hv_evmcs)
+       if (enable_shadow_vmcs || evmptr_is_valid(vmx->nested.hv_evmcs_vmptr))
                vmx->nested.need_vmcs12_to_shadow_sync = true;
        return NVMX_VMENTRY_VMEXIT;
 }
@@ -3493,7 +3492,8 @@ static int nested_vmx_run(struct kvm_vcpu *vcpu, bool launch)
                return nested_vmx_failInvalid(vcpu);
        }
 
-       if (CC(!vmx->nested.hv_evmcs && vmx->nested.current_vmptr == -1ull))
+       if (CC(!evmptr_is_valid(vmx->nested.hv_evmcs_vmptr) &&
+              vmx->nested.current_vmptr == -1ull))
                return nested_vmx_failInvalid(vcpu);
 
        vmcs12 = get_vmcs12(vcpu);
@@ -3507,7 +3507,7 @@ static int nested_vmx_run(struct kvm_vcpu *vcpu, bool launch)
        if (CC(vmcs12->hdr.shadow_vmcs))
                return nested_vmx_failInvalid(vcpu);
 
-       if (vmx->nested.hv_evmcs) {
+       if (evmptr_is_valid(vmx->nested.hv_evmcs_vmptr)) {
                copy_enlightened_to_vmcs12(vmx);
                /* Enlightened VMCS doesn't have launch state */
                vmcs12->launch_state = !launch;
@@ -4066,10 +4066,11 @@ static void sync_vmcs02_to_vmcs12(struct kvm_vcpu *vcpu, struct vmcs12 *vmcs12)
 {
        struct vcpu_vmx *vmx = to_vmx(vcpu);
 
-       if (vmx->nested.hv_evmcs)
+       if (evmptr_is_valid(vmx->nested.hv_evmcs_vmptr))
                sync_vmcs02_to_vmcs12_rare(vcpu, vmcs12);
 
-       vmx->nested.need_sync_vmcs02_to_vmcs12_rare = !vmx->nested.hv_evmcs;
+       vmx->nested.need_sync_vmcs02_to_vmcs12_rare =
+               !evmptr_is_valid(vmx->nested.hv_evmcs_vmptr);
 
        vmcs12->guest_cr0 = vmcs12_guest_cr0(vcpu, vmcs12);
        vmcs12->guest_cr4 = vmcs12_guest_cr4(vcpu, vmcs12);
@@ -4569,7 +4570,7 @@ void nested_vmx_vmexit(struct kvm_vcpu *vcpu, u32 vm_exit_reason,
        }
 
        if ((vm_exit_reason != -1) &&
-           (enable_shadow_vmcs || vmx->nested.hv_evmcs))
+           (enable_shadow_vmcs || evmptr_is_valid(vmx->nested.hv_evmcs_vmptr)))
                vmx->nested.need_vmcs12_to_shadow_sync = true;
 
        /* in case we halted in L2 */
@@ -5265,7 +5266,7 @@ static int handle_vmptrld(struct kvm_vcpu *vcpu)
                return nested_vmx_fail(vcpu, VMXERR_VMPTRLD_VMXON_POINTER);
 
        /* Forbid normal VMPTRLD if Enlightened version was used */
-       if (vmx->nested.hv_evmcs)
+       if (evmptr_is_valid(vmx->nested.hv_evmcs_vmptr))
                return 1;
 
        if (vmx->nested.current_vmptr != vmptr) {
@@ -5321,7 +5322,7 @@ static int handle_vmptrst(struct kvm_vcpu *vcpu)
        if (!nested_vmx_check_permission(vcpu))
                return 1;
 
-       if (unlikely(to_vmx(vcpu)->nested.hv_evmcs))
+       if (unlikely(evmptr_is_valid(to_vmx(vcpu)->nested.hv_evmcs_vmptr)))
                return 1;
 
        if (get_vmx_mem_address(vcpu, exit_qual, instr_info,
@@ -6093,7 +6094,7 @@ static int vmx_get_nested_state(struct kvm_vcpu *vcpu,
                if (vmx_has_valid_vmcs12(vcpu)) {
                        kvm_state.size += sizeof(user_vmx_nested_state->vmcs12);
 
-                       if (vmx->nested.hv_evmcs)
+                       if (evmptr_is_valid(vmx->nested.hv_evmcs_vmptr))
                                kvm_state.flags |= KVM_STATE_NESTED_EVMCS;
 
                        if (is_guest_mode(vcpu) &&
@@ -6149,7 +6150,7 @@ static int vmx_get_nested_state(struct kvm_vcpu *vcpu,
        } else  {
                copy_vmcs02_to_vmcs12_rare(vcpu, get_vmcs12(vcpu));
                if (!vmx->nested.need_vmcs12_to_shadow_sync) {
-                       if (vmx->nested.hv_evmcs)
+                       if (evmptr_is_valid(vmx->nested.hv_evmcs_vmptr))
                                copy_enlightened_to_vmcs12(vmx);
                        else if (enable_shadow_vmcs)
                                copy_shadow_to_vmcs12(vmx);

diff --git a/arch/x86/kvm/vmx/nested.h b/arch/x86/kvm/vmx/nested.h
index 184418b..c4397e8 100644 (file)
--- a/arch/x86/kvm/vmx/nested.h
+++ b/arch/x86/kvm/vmx/nested.h
@@ -63,7 +63,7 @@ static inline int vmx_has_valid_vmcs12(struct kvm_vcpu *vcpu)
         * have vmcs12 if it is true.
         */
        return is_guest_mode(vcpu) || vmx->nested.current_vmptr != -1ull ||
-               vmx->nested.hv_evmcs;
+               evmptr_is_valid(vmx->nested.hv_evmcs_vmptr);
 }
 
 static inline u16 nested_get_vpid02(struct kvm_vcpu *vcpu)

diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
index e3f744b..68a72c8 100644 (file)
--- a/arch/x86/kvm/vmx/vmx.c
+++ b/arch/x86/kvm/vmx/vmx.c
@@ -6861,6 +6861,7 @@ static int vmx_create_vcpu(struct kvm_vcpu *vcpu)
 
        vmx->nested.posted_intr_nv = -1;
        vmx->nested.current_vmptr = -1ull;
+       vmx->nested.hv_evmcs_vmptr = EVMPTR_INVALID;
 
        vcpu->arch.microcode_version = 0x100000000ULL;
        vmx->msr_ia32_feature_control_valid_bits = FEAT_CTL_LOCKED;