From c4660f9a4e2ffde711294ee7c5959f17735fd863 Mon Sep 17 00:00:00 2001
From: Paolo Bonzini <pbonzini@redhat.com>
Date: Thu, 6 Feb 2020 23:51:16 +0000
Subject: [PATCH 2/2] target/i386: kvm: initialize feature MSRs very early
RH-Author: Paolo Bonzini <pbonzini@redhat.com>
Message-id: <20200206235116.19421-2-pbonzini@redhat.com>
Patchwork-id: 93733
O-Subject: [PATCH 1/1] target/i386: kvm: initialize feature MSRs very early
Bugzilla: 1790308
RH-Acked-by: Vitaly Kuznetsov <vkuznets@redhat.com>
RH-Acked-by: Laszlo Ersek <lersek@redhat.com>
RH-Acked-by: Eduardo Habkost <ehabkost@redhat.com>
Some read-only MSRs affect the behavior of ioctls such as
KVM_SET_NESTED_STATE. We can initialize them once and for all
right after the CPU is realized, since they will never be modified
by the guest.
Reported-by: Qingua Cheng <qcheng@redhat.com>
Cc: qemu-stable@nongnu.org
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <1579544504-3616-2-git-send-email-pbonzini@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
(cherry picked from commit 420ae1fc51c99abfd03b1c590f55617edd2a2bed)
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Danilo C. L. de Paula <ddepaula@redhat.com>
---
target/i386/kvm.c | 81 ++++++++++++++++++++++++++++++--------------------
target/i386/kvm_i386.h | 1 +
2 files changed, 49 insertions(+), 33 deletions(-)
diff --git a/target/i386/kvm.c b/target/i386/kvm.c
index 92eda8d..e43bcd3 100644
--- a/target/i386/kvm.c
+++ b/target/i386/kvm.c
@@ -65,6 +65,8 @@
* 255 kvm_msr_entry structs */
#define MSR_BUF_SIZE 4096
+static void kvm_init_msrs(X86CPU *cpu);
+
const KVMCapabilityInfo kvm_arch_required_capabilities[] = {
KVM_CAP_INFO(SET_TSS_ADDR),
KVM_CAP_INFO(EXT_CPUID),
@@ -1296,6 +1298,8 @@ int kvm_arch_init_vcpu(CPUState *cs)
has_msr_tsc_aux = false;
}
+ kvm_init_msrs(cpu);
+
return 0;
fail:
@@ -2099,11 +2103,53 @@ static void kvm_msr_entry_add_vmx(X86CPU *cpu, FeatureWordArray f)
VMCS12_MAX_FIELD_INDEX << 1);
}
+static int kvm_buf_set_msrs(X86CPU *cpu)
+{
+ int ret = kvm_vcpu_ioctl(CPU(cpu), KVM_SET_MSRS, cpu->kvm_msr_buf);
+ if (ret < 0) {
+ return ret;
+ }
+
+ if (ret < cpu->kvm_msr_buf->nmsrs) {
+ struct kvm_msr_entry *e = &cpu->kvm_msr_buf->entries[ret];
+ error_report("error: failed to set MSR 0x%" PRIx32 " to 0x%" PRIx64,
+ (uint32_t)e->index, (uint64_t)e->data);
+ }
+
+ assert(ret == cpu->kvm_msr_buf->nmsrs);
+ return 0;
+}
+
+static void kvm_init_msrs(X86CPU *cpu)
+{
+ CPUX86State *env = &cpu->env;
+
+ kvm_msr_buf_reset(cpu);
+ if (has_msr_arch_capabs) {
+ kvm_msr_entry_add(cpu, MSR_IA32_ARCH_CAPABILITIES,
+ env->features[FEAT_ARCH_CAPABILITIES]);
+ }
+
+ if (has_msr_core_capabs) {
+ kvm_msr_entry_add(cpu, MSR_IA32_CORE_CAPABILITY,
+ env->features[FEAT_CORE_CAPABILITY]);
+ }
+
+ /*
+ * Older kernels do not include VMX MSRs in KVM_GET_MSR_INDEX_LIST, but
+ * all kernels with MSR features should have them.
+ */
+ if (kvm_feature_msrs && cpu_has_vmx(env)) {
+ kvm_msr_entry_add_vmx(cpu, env->features);
+ }
+
+ assert(kvm_buf_set_msrs(cpu) == 0);
+}
+
static int kvm_put_msrs(X86CPU *cpu, int level)
{
CPUX86State *env = &cpu->env;
int i;
- int ret;
kvm_msr_buf_reset(cpu);
@@ -2161,17 +2207,6 @@ static int kvm_put_msrs(X86CPU *cpu, int level)
}
#endif
- /* If host supports feature MSR, write down. */
- if (has_msr_arch_capabs) {
- kvm_msr_entry_add(cpu, MSR_IA32_ARCH_CAPABILITIES,
- env->features[FEAT_ARCH_CAPABILITIES]);
- }
-
- if (has_msr_core_capabs) {
- kvm_msr_entry_add(cpu, MSR_IA32_CORE_CAPABILITY,
- env->features[FEAT_CORE_CAPABILITY]);
- }
-
/*
* The following MSRs have side effects on the guest or are too heavy
* for normal writeback. Limit them to reset or full state updates.
@@ -2331,14 +2366,6 @@ static int kvm_put_msrs(X86CPU *cpu, int level)
/* Note: MSR_IA32_FEATURE_CONTROL is written separately, see
* kvm_put_msr_feature_control. */
-
- /*
- * Older kernels do not include VMX MSRs in KVM_GET_MSR_INDEX_LIST, but
- * all kernels with MSR features should have them.
- */
- if (kvm_feature_msrs && cpu_has_vmx(env)) {
- kvm_msr_entry_add_vmx(cpu, env->features);
- }
}
if (env->mcg_cap) {
@@ -2354,19 +2381,7 @@ static int kvm_put_msrs(X86CPU *cpu, int level)
}
}
- ret = kvm_vcpu_ioctl(CPU(cpu), KVM_SET_MSRS, cpu->kvm_msr_buf);
- if (ret < 0) {
- return ret;
- }
-
- if (ret < cpu->kvm_msr_buf->nmsrs) {
- struct kvm_msr_entry *e = &cpu->kvm_msr_buf->entries[ret];
- error_report("error: failed to set MSR 0x%" PRIx32 " to 0x%" PRIx64,
- (uint32_t)e->index, (uint64_t)e->data);
- }
-
- assert(ret == cpu->kvm_msr_buf->nmsrs);
- return 0;
+ return kvm_buf_set_msrs(cpu);
}
diff --git a/target/i386/kvm_i386.h b/target/i386/kvm_i386.h
index df9bbf3..5748337 100644
--- a/target/i386/kvm_i386.h
+++ b/target/i386/kvm_i386.h
@@ -70,4 +70,5 @@ void kvm_put_apicbase(X86CPU *cpu, uint64_t value);
bool kvm_enable_x2apic(void);
bool kvm_has_x2apic_api(void);
+
#endif
--
1.8.3.1