From: Xiaoyao Li <xiaoyao.li@intel.com>
To: Paolo Bonzini <pbonzini@redhat.com>,
Sean Christopherson <sean.j.christopherson@intel.com>
Cc: Vitaly Kuznetsov <vkuznets@redhat.com>,
Wanpeng Li <wanpengli@tencent.com>,
Jim Mattson <jmattson@google.com>, Joerg Roedel <joro@8bytes.org>,
kvm@vger.kernel.org, linux-kernel@vger.kernel.org,
Xiaoyao Li <xiaoyao.li@intel.com>
Subject: [PATCH v4 1/5] KVM: x86: Introduce kvm_check_cpuid()
Date: Thu, 9 Jul 2020 12:34:22 +0800 [thread overview]
Message-ID: <20200709043426.92712-2-xiaoyao.li@intel.com> (raw)
In-Reply-To: <20200709043426.92712-1-xiaoyao.li@intel.com>
Use kvm_check_cpuid() to validate if userspace provides legal cpuid
settings and call it before KVM take any action to update CPUID or
update vcpu states based on given CPUID settings.
Signed-off-by: Xiaoyao Li <xiaoyao.li@intel.com>
---
arch/x86/kvm/cpuid.c | 55 ++++++++++++++++++++++++++++----------------
arch/x86/kvm/cpuid.h | 2 +-
2 files changed, 36 insertions(+), 21 deletions(-)
diff --git a/arch/x86/kvm/cpuid.c b/arch/x86/kvm/cpuid.c
index eebd66f86abe..1a053022a961 100644
--- a/arch/x86/kvm/cpuid.c
+++ b/arch/x86/kvm/cpuid.c
@@ -54,7 +54,26 @@ static u32 xstate_required_size(u64 xstate_bv, bool compacted)
#define F feature_bit
-int kvm_update_cpuid(struct kvm_vcpu *vcpu)
+static int kvm_check_cpuid(struct kvm_vcpu *vcpu)
+{
+ struct kvm_cpuid_entry2 *best;
+
+ /*
+ * The existing code assumes virtual address is 48-bit or 57-bit in the
+ * canonical address checks; exit if it is ever changed.
+ */
+ best = kvm_find_cpuid_entry(vcpu, 0x80000008, 0);
+ if (best) {
+ int vaddr_bits = (best->eax & 0xff00) >> 8;
+
+ if (vaddr_bits != 48 && vaddr_bits != 57 && vaddr_bits != 0)
+ return -EINVAL;
+ }
+
+ return 0;
+}
+
+void kvm_update_cpuid(struct kvm_vcpu *vcpu)
{
struct kvm_cpuid_entry2 *best;
struct kvm_lapic *apic = vcpu->arch.apic;
@@ -98,18 +117,6 @@ int kvm_update_cpuid(struct kvm_vcpu *vcpu)
cpuid_entry_has(best, X86_FEATURE_XSAVEC)))
best->ebx = xstate_required_size(vcpu->arch.xcr0, true);
- /*
- * The existing code assumes virtual address is 48-bit or 57-bit in the
- * canonical address checks; exit if it is ever changed.
- */
- best = kvm_find_cpuid_entry(vcpu, 0x80000008, 0);
- if (best) {
- int vaddr_bits = (best->eax & 0xff00) >> 8;
-
- if (vaddr_bits != 48 && vaddr_bits != 57 && vaddr_bits != 0)
- return -EINVAL;
- }
-
best = kvm_find_cpuid_entry(vcpu, KVM_CPUID_FEATURES, 0);
if (kvm_hlt_in_guest(vcpu->kvm) && best &&
(best->eax & (1 << KVM_FEATURE_PV_UNHALT)))
@@ -131,7 +138,6 @@ int kvm_update_cpuid(struct kvm_vcpu *vcpu)
kvm_pmu_refresh(vcpu);
vcpu->arch.cr4_guest_rsvd_bits =
__cr4_reserved_bits(guest_cpuid_has, vcpu);
- return 0;
}
static int is_efer_nx(void)
@@ -206,11 +212,16 @@ int kvm_vcpu_ioctl_set_cpuid(struct kvm_vcpu *vcpu,
vcpu->arch.cpuid_entries[i].padding[2] = 0;
}
vcpu->arch.cpuid_nent = cpuid->nent;
+ r = kvm_check_cpuid(vcpu);
+ if (r) {
+ vcpu->arch.cpuid_nent = 0;
+ kvfree(cpuid_entries);
+ goto out;
+ }
+
cpuid_fix_nx_cap(vcpu);
kvm_x86_ops.cpuid_update(vcpu);
- r = kvm_update_cpuid(vcpu);
- if (r)
- vcpu->arch.cpuid_nent = 0;
+ kvm_update_cpuid(vcpu);
kvfree(cpuid_entries);
out:
@@ -231,10 +242,14 @@ int kvm_vcpu_ioctl_set_cpuid2(struct kvm_vcpu *vcpu,
cpuid->nent * sizeof(struct kvm_cpuid_entry2)))
goto out;
vcpu->arch.cpuid_nent = cpuid->nent;
- kvm_x86_ops.cpuid_update(vcpu);
- r = kvm_update_cpuid(vcpu);
- if (r)
+ r = kvm_check_cpuid(vcpu);
+ if (r) {
vcpu->arch.cpuid_nent = 0;
+ goto out;
+ }
+
+ kvm_x86_ops.cpuid_update(vcpu);
+ kvm_update_cpuid(vcpu);
out:
return r;
}
diff --git a/arch/x86/kvm/cpuid.h b/arch/x86/kvm/cpuid.h
index 05434cd9342f..f136de1debad 100644
--- a/arch/x86/kvm/cpuid.h
+++ b/arch/x86/kvm/cpuid.h
@@ -9,7 +9,7 @@
extern u32 kvm_cpu_caps[NCAPINTS] __read_mostly;
void kvm_set_cpu_caps(void);
-int kvm_update_cpuid(struct kvm_vcpu *vcpu);
+void kvm_update_cpuid(struct kvm_vcpu *vcpu);
struct kvm_cpuid_entry2 *kvm_find_cpuid_entry(struct kvm_vcpu *vcpu,
u32 function, u32 index);
int kvm_dev_ioctl_get_cpuid(struct kvm_cpuid2 *cpuid,
--
2.18.4
next prev parent reply other threads:[~2020-07-09 4:34 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-07-09 4:34 [PATCH v4 0/5] Refactor handling flow of KVM_SET_CPUID* Xiaoyao Li
2020-07-09 4:34 ` Xiaoyao Li [this message]
2020-07-09 4:34 ` [PATCH v4 2/5] KVM: x86: Extract kvm_update_cpuid_runtime() from kvm_update_cpuid() Xiaoyao Li
2020-07-09 10:55 ` Paolo Bonzini
2020-07-09 4:34 ` [PATCH v4 3/5] KVM: x86: Rename kvm_update_cpuid() to kvm_vcpu_after_set_cpuid() Xiaoyao Li
2020-07-09 4:34 ` [PATCH v4 4/5] KVM: x86: Rename cpuid_update() callback to vcpu_after_set_cpuid() Xiaoyao Li
2020-07-09 4:34 ` [PATCH v4 5/5] KVM: x86: Move kvm_x86_ops.vcpu_after_set_cpuid() into kvm_vcpu_after_set_cpuid() Xiaoyao Li
2020-07-09 11:08 ` [PATCH v4 0/5] Refactor handling flow of KVM_SET_CPUID* Paolo Bonzini
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