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authorGreg Kroah-Hartman <gregkh@linuxfoundation.org>2026-07-24 16:21:27 +0200
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2026-07-24 16:21:27 +0200
commit8f9aa2c90530ab92301a82231ae44f3722becd93 (patch)
treefb282e955b0a880b07131a135257fe3ec764e928 /arch/x86/kvm
parent93467b31bec6da512b51544e5e4584f2745e995e (diff)
parent155b42bec9cbb6b8cdc47dd9bd09503a81fbe493 (diff)
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'arch/x86/kvm')
-rw-r--r--arch/x86/kvm/irq.c4
-rw-r--r--arch/x86/kvm/lapic.c8
-rw-r--r--arch/x86/kvm/svm/sev.c6
-rw-r--r--arch/x86/kvm/vmx/nested.c68
-rw-r--r--arch/x86/kvm/vmx/tdx.c6
5 files changed, 49 insertions, 43 deletions
diff --git a/arch/x86/kvm/irq.c b/arch/x86/kvm/irq.c
index 9519fec09ee6..c5c2f778c669 100644
--- a/arch/x86/kvm/irq.c
+++ b/arch/x86/kvm/irq.c
@@ -488,8 +488,10 @@ int kvm_arch_irq_bypass_add_producer(struct irq_bypass_consumer *cons,
if (irqfd->irq_entry.type == KVM_IRQ_ROUTING_MSI) {
ret = kvm_pi_update_irte(irqfd, &irqfd->irq_entry);
- if (ret)
+ if (ret) {
kvm->arch.nr_possible_bypass_irqs--;
+ irqfd->producer = NULL;
+ }
}
spin_unlock_irq(&kvm->irqfds.lock);
diff --git a/arch/x86/kvm/lapic.c b/arch/x86/kvm/lapic.c
index 92a1e69c5962..d806abaeda3d 100644
--- a/arch/x86/kvm/lapic.c
+++ b/arch/x86/kvm/lapic.c
@@ -3371,6 +3371,12 @@ static void apic_sync_pv_eoi_from_guest(struct kvm_vcpu *vcpu,
struct kvm_lapic *apic)
{
int vector;
+
+ if (unlikely(!pv_eoi_enabled(vcpu))) {
+ __clear_bit(KVM_APIC_PV_EOI_PENDING, &vcpu->arch.apic_attention);
+ return;
+ }
+
/*
* PV EOI state is derived from KVM_APIC_PV_EOI_PENDING in host
* and KVM_PV_EOI_ENABLED in guest memory as follows:
@@ -3382,8 +3388,6 @@ static void apic_sync_pv_eoi_from_guest(struct kvm_vcpu *vcpu,
* KVM_APIC_PV_EOI_PENDING is set, KVM_PV_EOI_ENABLED is unset:
* -> host enabled PV EOI, guest executed EOI.
*/
- BUG_ON(!pv_eoi_enabled(vcpu));
-
if (pv_eoi_test_and_clr_pending(vcpu))
return;
vector = apic_set_eoi(apic);
diff --git a/arch/x86/kvm/svm/sev.c b/arch/x86/kvm/svm/sev.c
index d90f5a41e340..996f398a577f 100644
--- a/arch/x86/kvm/svm/sev.c
+++ b/arch/x86/kvm/svm/sev.c
@@ -2142,8 +2142,9 @@ int sev_vm_move_enc_context_from(struct kvm *kvm, unsigned int source_fd)
if (ret)
return ret;
+ /* Do not allow SNP VM migration until additional state transfer is implemented */
if (kvm->arch.vm_type != source_kvm->arch.vm_type ||
- sev_guest(kvm) || !sev_guest(source_kvm)) {
+ sev_guest(kvm) || !sev_guest(source_kvm) || sev_snp_guest(source_kvm)) {
ret = -EINVAL;
goto out_unlock;
}
@@ -2865,8 +2866,9 @@ int sev_vm_copy_enc_context_from(struct kvm *kvm, unsigned int source_fd)
* disallow out-of-band SEV/SEV-ES init if the target is already an
* SEV guest, or if vCPUs have been created. KVM relies on vCPUs being
* created after SEV/SEV-ES initialization, e.g. to init intercepts.
+ * Also do not allow SNP VM mirroring until additional state transfer is implemented.
*/
- if (sev_guest(kvm) || !sev_guest(source_kvm) ||
+ if (sev_guest(kvm) || !sev_guest(source_kvm) || sev_snp_guest(source_kvm) ||
is_mirroring_enc_context(source_kvm) || kvm->created_vcpus) {
ret = -EINVAL;
goto e_unlock;
diff --git a/arch/x86/kvm/vmx/nested.c b/arch/x86/kvm/vmx/nested.c
index 3fe88f29be7a..52ab52b0e1cc 100644
--- a/arch/x86/kvm/vmx/nested.c
+++ b/arch/x86/kvm/vmx/nested.c
@@ -553,6 +553,9 @@ static int nested_vmx_check_msr_bitmap_controls(struct kvm_vcpu *vcpu,
static int nested_vmx_check_tpr_shadow_controls(struct kvm_vcpu *vcpu,
struct vmcs12 *vmcs12)
{
+ gpa_t vtpr_gpa = vmcs12->virtual_apic_page_addr + APIC_TASKPRI;
+ u32 vtpr;
+
if (!nested_cpu_has(vmcs12, CPU_BASED_TPR_SHADOW))
return 0;
@@ -562,6 +565,32 @@ static int nested_vmx_check_tpr_shadow_controls(struct kvm_vcpu *vcpu,
if (CC(!nested_cpu_has_vid(vmcs12) && vmcs12->tpr_threshold >> 4))
return -EINVAL;
+ /*
+ * Do the illegal vTPR vs. TPR Threshold consistency check if and only
+ * if KVM is configured to WARN on missed consistency checks, otherwise
+ * it's a waste of time. KVM needs to rely on hardware to fully detect
+ * an illegal combination due to the vTPR being writable by L1 at all
+ * times (it's an in-memory value, not a VMCS field). I.e. even if the
+ * check passes now, it might fail at the actual VM-Enter.
+ *
+ * If reading guest memory fails, skip the check as KVM's de facto ABI
+ * for VMX instruction accesses to non-existent memory is to provide
+ * PCI Bus Error semantics (reads return 0xFFs), in which case the vTPR
+ * is guaranteed to greater than or equal to the threshold.
+ *
+ * Note! Deliberately use the VM-scoped API when reading guest memory,
+ * to ensure the read doesn't hit SMRAM when restoring L2 state on RSM,
+ * and only perform the check when in KVM_RUN, to avoid a false failure
+ * if userspace hasn't yet configured memslots during state restore.
+ */
+ if (warn_on_missed_cc && vcpu->wants_to_run &&
+ nested_cpu_has(vmcs12, CPU_BASED_TPR_SHADOW) &&
+ !nested_cpu_has_vid(vmcs12) &&
+ !nested_cpu_has2(vmcs12, SECONDARY_EXEC_VIRTUALIZE_APIC_ACCESSES) &&
+ !kvm_read_guest(vcpu->kvm, vtpr_gpa, &vtpr, sizeof(vtpr)) &&
+ CC((vmcs12->tpr_threshold & GENMASK(3, 0)) > ((vtpr >> 4) & GENMASK(3, 0))))
+ return -EINVAL;
+
return 0;
}
@@ -3085,38 +3114,6 @@ static int nested_vmx_check_controls(struct kvm_vcpu *vcpu,
return 0;
}
-static int nested_vmx_check_controls_late(struct kvm_vcpu *vcpu,
- struct vmcs12 *vmcs12)
-{
- void *vapic = to_vmx(vcpu)->nested.virtual_apic_map.hva;
- u32 vtpr = vapic ? (*(u32 *)(vapic + APIC_TASKPRI)) >> 4 : 0;
-
- /*
- * Don't bother with the consistency checks if KVM isn't configured to
- * WARN on missed consistency checks, as KVM needs to rely on hardware
- * to fully detect an illegal vTPR vs. TRP Threshold combination due to
- * the vTPR being writable by L1 at all times (it's an in-memory value,
- * not a VMCS field). I.e. even if the check passes now, it might fail
- * at the actual VM-Enter.
- *
- * Keying off the module param also allows treating an invalid vAPIC
- * mapping as a consistency check failure without increasing the risk
- * of breaking a "real" VM.
- */
- if (!warn_on_missed_cc)
- return 0;
-
- if ((exec_controls_get(to_vmx(vcpu)) & CPU_BASED_TPR_SHADOW) &&
- nested_cpu_has(vmcs12, CPU_BASED_TPR_SHADOW) &&
- !nested_cpu_has_vid(vmcs12) &&
- !nested_cpu_has2(vmcs12, SECONDARY_EXEC_VIRTUALIZE_APIC_ACCESSES) &&
- (CC(!vapic) ||
- CC((vmcs12->tpr_threshold & GENMASK(3, 0)) > (vtpr & GENMASK(3, 0)))))
- return -EINVAL;
-
- return 0;
-}
-
static int nested_vmx_check_address_space_size(struct kvm_vcpu *vcpu,
struct vmcs12 *vmcs12)
{
@@ -3666,11 +3663,6 @@ enum nvmx_vmentry_status nested_vmx_enter_non_root_mode(struct kvm_vcpu *vcpu,
return NVMX_VMENTRY_KVM_INTERNAL_ERROR;
}
- if (nested_vmx_check_controls_late(vcpu, vmcs12)) {
- vmx_switch_vmcs(vcpu, &vmx->vmcs01);
- return NVMX_VMENTRY_VMFAIL;
- }
-
if (nested_vmx_check_guest_state(vcpu, vmcs12,
&entry_failure_code)) {
exit_reason.basic = EXIT_REASON_INVALID_STATE;
@@ -3755,6 +3747,8 @@ vmentry_fail_vmexit:
if (!from_vmentry)
return NVMX_VMENTRY_VMEXIT;
+ nested_put_vmcs12_pages(vcpu);
+
load_vmcs12_host_state(vcpu, vmcs12);
vmcs12->vm_exit_reason = exit_reason.full;
if (enable_shadow_vmcs || nested_vmx_is_evmptr12_valid(vmx))
diff --git a/arch/x86/kvm/vmx/tdx.c b/arch/x86/kvm/vmx/tdx.c
index ec29a2db1adc..556bf9fe1f5d 100644
--- a/arch/x86/kvm/vmx/tdx.c
+++ b/arch/x86/kvm/vmx/tdx.c
@@ -2725,7 +2725,11 @@ static int tdx_td_init(struct kvm *kvm, struct kvm_tdx_cmd *cmd)
goto out;
}
- if (init_vm->cpuid.padding) {
+ /*
+ * Reject the request if userspace changes cpuid.nent between the
+ * initial read and the subsequent copy.
+ */
+ if (init_vm->cpuid.padding || init_vm->cpuid.nent != nr_user_entries) {
ret = -EINVAL;
goto out;
}