KVM: VMX: Wrap all accesses to IA32_DEBUGCTL with getter/setter APIs

Introduce vmx_guest_debugctl_{read,write}() to handle all accesses to
vmcs.GUEST_IA32_DEBUGCTL. This will allow stuffing FREEZE_IN_SMM into
GUEST_IA32_DEBUGCTL based on the host setting without bleeding the state
into the guest, and without needing to copy+paste the FREEZE_IN_SMM
logic into every patch that accesses GUEST_IA32_DEBUGCTL.

No functional change intended.

Cc: stable@vger.kernel.org
Signed-off-by: Maxim Levitsky <mlevitsk@redhat.com>
[sean: massage changelog, make inline, use in all prepare_vmcs02() cases]
Reviewed-by: Dapeng Mi <dapeng1.mi@linux.intel.com>
Link: https://lore.kernel.org/r/20250610232010.162191-8-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>

diff --git a/arch/x86/kvm/vmx/nested.c b/arch/x86/kvm/vmx/nested.c
index 1b8b0642fc2d63f5a4f9acfcdd0a914cf832c90a..ef20184b8b11815539e3302675f0822f500c158c 100644 (file)
--- a/arch/x86/kvm/vmx/nested.c
+++ b/arch/x86/kvm/vmx/nested.c
@@ -2663,11 +2663,11 @@ static int prepare_vmcs02(struct kvm_vcpu *vcpu, struct vmcs12 *vmcs12,
        if (vmx->nested.nested_run_pending &&
            (vmcs12->vm_entry_controls & VM_ENTRY_LOAD_DEBUG_CONTROLS)) {
                kvm_set_dr(vcpu, 7, vmcs12->guest_dr7);
-               vmcs_write64(GUEST_IA32_DEBUGCTL, vmcs12->guest_ia32_debugctl &
-                                                 vmx_get_supported_debugctl(vcpu, false));
+               vmx_guest_debugctl_write(vcpu, vmcs12->guest_ia32_debugctl &
+                                              vmx_get_supported_debugctl(vcpu, false));
        } else {
                kvm_set_dr(vcpu, 7, vcpu->arch.dr7);
-               vmcs_write64(GUEST_IA32_DEBUGCTL, vmx->nested.pre_vmenter_debugctl);
+               vmx_guest_debugctl_write(vcpu, vmx->nested.pre_vmenter_debugctl);
        }
        if (kvm_mpx_supported() && (!vmx->nested.nested_run_pending ||
            !(vmcs12->vm_entry_controls & VM_ENTRY_LOAD_BNDCFGS)))
@@ -3532,7 +3532,7 @@ enum nvmx_vmentry_status nested_vmx_enter_non_root_mode(struct kvm_vcpu *vcpu,
 
        if (!vmx->nested.nested_run_pending ||
            !(vmcs12->vm_entry_controls & VM_ENTRY_LOAD_DEBUG_CONTROLS))
-               vmx->nested.pre_vmenter_debugctl = vmcs_read64(GUEST_IA32_DEBUGCTL);
+               vmx->nested.pre_vmenter_debugctl = vmx_guest_debugctl_read();
        if (kvm_mpx_supported() &&
            (!vmx->nested.nested_run_pending ||
             !(vmcs12->vm_entry_controls & VM_ENTRY_LOAD_BNDCFGS)))
@@ -4806,7 +4806,7 @@ static void load_vmcs12_host_state(struct kvm_vcpu *vcpu,
        __vmx_set_segment(vcpu, &seg, VCPU_SREG_LDTR);
 
        kvm_set_dr(vcpu, 7, 0x400);
-       vmcs_write64(GUEST_IA32_DEBUGCTL, 0);
+       vmx_guest_debugctl_write(vcpu, 0);
 
        if (nested_vmx_load_msr(vcpu, vmcs12->vm_exit_msr_load_addr,
                                vmcs12->vm_exit_msr_load_count))

diff --git a/arch/x86/kvm/vmx/pmu_intel.c b/arch/x86/kvm/vmx/pmu_intel.c
index bbf4509f32d0fd56a7f0f3586199fbdaf6c7d3e2..0b173602821ba37f483e85e0d4daa8bec991e03d 100644 (file)
--- a/arch/x86/kvm/vmx/pmu_intel.c
+++ b/arch/x86/kvm/vmx/pmu_intel.c
@@ -653,11 +653,11 @@ static void intel_pmu_reset(struct kvm_vcpu *vcpu)
  */
 static void intel_pmu_legacy_freezing_lbrs_on_pmi(struct kvm_vcpu *vcpu)
 {
-       u64 data = vmcs_read64(GUEST_IA32_DEBUGCTL);
+       u64 data = vmx_guest_debugctl_read();
 
        if (data & DEBUGCTLMSR_FREEZE_LBRS_ON_PMI) {
                data &= ~DEBUGCTLMSR_LBR;
-               vmcs_write64(GUEST_IA32_DEBUGCTL, data);
+               vmx_guest_debugctl_write(vcpu, data);
        }
 }
 
@@ -730,7 +730,7 @@ void vmx_passthrough_lbr_msrs(struct kvm_vcpu *vcpu)
 
        if (!lbr_desc->event) {
                vmx_disable_lbr_msrs_passthrough(vcpu);
-               if (vmcs_read64(GUEST_IA32_DEBUGCTL) & DEBUGCTLMSR_LBR)
+               if (vmx_guest_debugctl_read() & DEBUGCTLMSR_LBR)
                        goto warn;
                if (test_bit(INTEL_PMC_IDX_FIXED_VLBR, pmu->pmc_in_use))
                        goto warn;
@@ -752,7 +752,7 @@ warn:
 
 static void intel_pmu_cleanup(struct kvm_vcpu *vcpu)
 {
-       if (!(vmcs_read64(GUEST_IA32_DEBUGCTL) & DEBUGCTLMSR_LBR))
+       if (!(vmx_guest_debugctl_read() & DEBUGCTLMSR_LBR))
                intel_pmu_release_guest_lbr_event(vcpu);
 }
 

diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
index 6a8b78e954cd9d79d9abb637705e0aa15d29dce6..a77d325fe78b5d06ff0cc7d0265b78aca3ad1f55 100644 (file)
--- a/arch/x86/kvm/vmx/vmx.c
+++ b/arch/x86/kvm/vmx/vmx.c
@@ -2149,7 +2149,7 @@ int vmx_get_msr(struct kvm_vcpu *vcpu, struct msr_data *msr_info)
                        msr_info->data = vmx->pt_desc.guest.addr_a[index / 2];
                break;
        case MSR_IA32_DEBUGCTLMSR:
-               msr_info->data = vmcs_read64(GUEST_IA32_DEBUGCTL);
+               msr_info->data = vmx_guest_debugctl_read();
                break;
        default:
        find_uret_msr:
@@ -2283,7 +2283,8 @@ int vmx_set_msr(struct kvm_vcpu *vcpu, struct msr_data *msr_info)
                                                VM_EXIT_SAVE_DEBUG_CONTROLS)
                        get_vmcs12(vcpu)->guest_ia32_debugctl = data;
 
-               vmcs_write64(GUEST_IA32_DEBUGCTL, data);
+               vmx_guest_debugctl_write(vcpu, data);
+
                if (intel_pmu_lbr_is_enabled(vcpu) && !to_vmx(vcpu)->lbr_desc.event &&
                    (data & DEBUGCTLMSR_LBR))
                        intel_pmu_create_guest_lbr_event(vcpu);
@@ -4798,7 +4799,8 @@ static void init_vmcs(struct vcpu_vmx *vmx)
        vmcs_write32(GUEST_SYSENTER_CS, 0);
        vmcs_writel(GUEST_SYSENTER_ESP, 0);
        vmcs_writel(GUEST_SYSENTER_EIP, 0);
-       vmcs_write64(GUEST_IA32_DEBUGCTL, 0);
+
+       vmx_guest_debugctl_write(&vmx->vcpu, 0);
 
        if (cpu_has_vmx_tpr_shadow()) {
                vmcs_write64(VIRTUAL_APIC_PAGE_ADDR, 0);

diff --git a/arch/x86/kvm/vmx/vmx.h b/arch/x86/kvm/vmx/vmx.h
index 392e66c7e5fe4775f433a0b3f29431675dc0d94f..c20a4185d10ad8f065db326d10f8f906a697b847 100644 (file)
--- a/arch/x86/kvm/vmx/vmx.h
+++ b/arch/x86/kvm/vmx/vmx.h
@@ -417,6 +417,16 @@ void vmx_update_cpu_dirty_logging(struct kvm_vcpu *vcpu);
 u64 vmx_get_supported_debugctl(struct kvm_vcpu *vcpu, bool host_initiated);
 bool vmx_is_valid_debugctl(struct kvm_vcpu *vcpu, u64 data, bool host_initiated);
 
+static inline void vmx_guest_debugctl_write(struct kvm_vcpu *vcpu, u64 val)
+{
+       vmcs_write64(GUEST_IA32_DEBUGCTL, val);
+}
+
+static inline u64 vmx_guest_debugctl_read(void)
+{
+       return vmcs_read64(GUEST_IA32_DEBUGCTL);
+}
+
 /*
  * Note, early Intel manuals have the write-low and read-high bitmap offsets
  * the wrong way round.  The bitmaps control MSRs 0x00000000-0x00001fff and