From: Maxim Levitsky <mlevitsk@xxxxxxxxxx>
Neither of these settings should be changed by the guest and it is a burden
to support it in the acceleration code, so just inhibit APICv/AVIC in case
such rare cases happen.
Signed-off-by: Maxim Levitsky <mlevitsk@xxxxxxxxxx>
Signed-off-by: Zeng Guang <guang.zeng@xxxxxxxxx>
---
arch/x86/include/asm/kvm_host.h | 1 +
arch/x86/kvm/lapic.c | 25 +++++++++++++++++++++----
arch/x86/kvm/lapic.h | 8 ++++++++
arch/x86/kvm/svm/avic.c | 3 ++-
arch/x86/kvm/vmx/vmx.c | 3 ++-
5 files changed, 34 insertions(+), 6 deletions(-)
diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index 4ff36610af6a..408cf88351dd 100644
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -1051,6 +1051,7 @@ enum kvm_apicv_inhibit {
APICV_INHIBIT_REASON_BLOCKIRQ,
APICV_INHIBIT_REASON_ABSENT,
APICV_INHIBIT_REASON_SEV,
+ APICV_INHIBIT_REASON_RO_SETTINGS,
};
struct kvm_arch {
diff --git a/arch/x86/kvm/lapic.c b/arch/x86/kvm/lapic.c
index 66b0eb0bda94..f256fa974ea3 100644
--- a/arch/x86/kvm/lapic.c
+++ b/arch/x86/kvm/lapic.c
@@ -2038,6 +2038,17 @@ static void apic_manage_nmi_watchdog(struct kvm_lapic *apic, u32 lvt0_val)
}
}
+static void kvm_lapic_check_initial_apic_id(struct kvm_lapic *apic)
+{
+ if (kvm_apic_has_initial_apic_id(apic))
+ return;
+
+ pr_warn_once("APIC ID change is unexpected by KVM");
+
+ kvm_set_apicv_inhibit(apic->vcpu->kvm,
+ APICV_INHIBIT_REASON_RO_SETTINGS);
+}
+
static int kvm_lapic_reg_write(struct kvm_lapic *apic, u32 reg, u32 val)
{
int ret = 0;
@@ -2046,9 +2057,11 @@ static int kvm_lapic_reg_write(struct kvm_lapic *apic, u32 reg, u32 val)
switch (reg) {
case APIC_ID: /* Local APIC ID */
- if (!apic_x2apic_mode(apic))
+ if (!apic_x2apic_mode(apic)) {
+
kvm_apic_set_xapic_id(apic, val >> 24);
- else
+ kvm_lapic_check_initial_apic_id(apic);
+ } else
ret = 1;
break;
@@ -2335,8 +2348,11 @@ void kvm_lapic_set_base(struct kvm_vcpu *vcpu, u64 value)
MSR_IA32_APICBASE_BASE;
if ((value & MSR_IA32_APICBASE_ENABLE) &&
- apic->base_address != APIC_DEFAULT_PHYS_BASE)
- pr_warn_once("APIC base relocation is unsupported by KVM");
+ apic->base_address != APIC_DEFAULT_PHYS_BASE) {
+ kvm_set_apicv_inhibit(apic->vcpu->kvm,
+ APICV_INHIBIT_REASON_RO_SETTINGS);
+ pr_warn_once("APIC base relocation is unexpected by KVM");
+ }
}
void kvm_apic_update_apicv(struct kvm_vcpu *vcpu)
@@ -2649,6 +2665,7 @@ static int kvm_apic_state_fixup(struct kvm_vcpu *vcpu,
}
}
+ kvm_lapic_check_initial_apic_id(vcpu->arch.apic);
return 0;
}
diff --git a/arch/x86/kvm/lapic.h b/arch/x86/kvm/lapic.h
index 4e4f8a22754f..b9c406d38308 100644
--- a/arch/x86/kvm/lapic.h
+++ b/arch/x86/kvm/lapic.h
@@ -252,4 +252,12 @@ static inline u8 kvm_xapic_id(struct kvm_lapic *apic)
return kvm_lapic_get_reg(apic, APIC_ID) >> 24;
}
+static inline bool kvm_apic_has_initial_apic_id(struct kvm_lapic *apic)
+{
+ if (apic_x2apic_mode(apic))
+ return true;
+
+ return kvm_xapic_id(apic) == apic->vcpu->vcpu_id;
+}
+
#endif
diff --git a/arch/x86/kvm/svm/avic.c b/arch/x86/kvm/svm/avic.c
index 421619540ff9..04a07b82b1a4 100644
--- a/arch/x86/kvm/svm/avic.c
+++ b/arch/x86/kvm/svm/avic.c
@@ -838,7 +838,8 @@ bool avic_check_apicv_inhibit_reasons(enum kvm_apicv_inhibit reason)
BIT(APICV_INHIBIT_REASON_PIT_REINJ) |
BIT(APICV_INHIBIT_REASON_X2APIC) |
BIT(APICV_INHIBIT_REASON_BLOCKIRQ) |
- BIT(APICV_INHIBIT_REASON_SEV);
+ BIT(APICV_INHIBIT_REASON_SEV) |
+ BIT(APICV_INHIBIT_REASON_RO_SETTINGS);
return supported & BIT(reason);
}
diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
index 610355b9ccce..b31f858cacf2 100644
--- a/arch/x86/kvm/vmx/vmx.c
+++ b/arch/x86/kvm/vmx/vmx.c
@@ -7710,7 +7710,8 @@ static bool vmx_check_apicv_inhibit_reasons(enum kvm_apicv_inhibit reason)
ulong supported = BIT(APICV_INHIBIT_REASON_DISABLE) |
BIT(APICV_INHIBIT_REASON_ABSENT) |
BIT(APICV_INHIBIT_REASON_HYPERV) |
- BIT(APICV_INHIBIT_REASON_BLOCKIRQ);
+ BIT(APICV_INHIBIT_REASON_BLOCKIRQ) |
+ BIT(APICV_INHIBIT_REASON_RO_SETTINGS);
return supported & BIT(reason);
}
--
2.27.0
