blob: dd22d1790c04b2c954d6bcdbefce0a24d8953065 [file] [log] [blame]
From 8343a24295977b9ae73e8f50c6c876774c9bb3a0 Mon Sep 17 00:00:00 2001
From: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Date: Fri, 6 Dec 2019 15:36:12 +0000
Subject: [PATCH] x86/KVM: Clean up host's steal time structure
commit a6bd811f1209fe1c64c9f6fd578101d6436c6b6e upstream.
Now that we are mapping kvm_steal_time from the guest directly we
don't need keep a copy of it in kvm_vcpu_arch.st. The same is true
for the stime field.
This is part of CVE-2019-3016.
Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Reviewed-by: Joao Martins <joao.m.martins@oracle.com>
Cc: stable@vger.kernel.org
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index 4c8704f579d4..83350f210be9 100644
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -672,10 +672,9 @@ struct kvm_vcpu_arch {
bool pvclock_set_guest_stopped_request;
struct {
+ u8 preempted;
u64 msr_val;
u64 last_steal;
- struct gfn_to_hva_cache stime;
- struct kvm_steal_time steal;
struct gfn_to_pfn_cache cache;
} st;
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index a35d662fd71c..0e2fd2941068 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -2495,7 +2495,7 @@ static void record_steal_time(struct kvm_vcpu *vcpu)
if (xchg(&st->preempted, 0) & KVM_VCPU_FLUSH_TLB)
kvm_vcpu_flush_tlb(vcpu, false);
- vcpu->arch.st.steal.preempted = 0;
+ vcpu->arch.st.preempted = 0;
if (st->version & 1)
st->version += 1; /* first time write, random junk */
@@ -2657,11 +2657,6 @@ int kvm_set_msr_common(struct kvm_vcpu *vcpu, struct msr_data *msr_info)
if (data & KVM_STEAL_RESERVED_MASK)
return 1;
- if (kvm_gfn_to_hva_cache_init(vcpu->kvm, &vcpu->arch.st.stime,
- data & KVM_STEAL_VALID_BITS,
- sizeof(struct kvm_steal_time)))
- return 1;
-
vcpu->arch.st.msr_val = data;
if (!(data & KVM_MSR_ENABLED))
@@ -3363,7 +3358,7 @@ static void kvm_steal_time_set_preempted(struct kvm_vcpu *vcpu)
if (!(vcpu->arch.st.msr_val & KVM_MSR_ENABLED))
return;
- if (vcpu->arch.st.steal.preempted)
+ if (vcpu->arch.st.preempted)
return;
if (kvm_map_gfn(vcpu, vcpu->arch.st.msr_val >> PAGE_SHIFT, &map,
@@ -3373,7 +3368,7 @@ static void kvm_steal_time_set_preempted(struct kvm_vcpu *vcpu)
st = map.hva +
offset_in_page(vcpu->arch.st.msr_val & KVM_STEAL_VALID_BITS);
- st->preempted = vcpu->arch.st.steal.preempted = KVM_VCPU_PREEMPTED;
+ st->preempted = vcpu->arch.st.preempted = KVM_VCPU_PREEMPTED;
kvm_unmap_gfn(vcpu, &map, &vcpu->arch.st.cache, true, true);
}
--
2.7.4