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authorLinus Torvalds <torvalds@woody.linux-foundation.org>2007-06-15 16:14:34 -0700
committerLinus Torvalds <torvalds@woody.linux-foundation.org>2007-06-15 16:14:34 -0700
commit3ea88d6738ebda95e05ada0c7b72f224d0a36953 (patch)
treeb087d4d9d978556d6f673d8ce93489ef2b0da9ad
parent4ff4275b24fdcca189b33f9a73fe7abef1dc84bc (diff)
parent7702fd1f6fea57921f2e643d27a23a2d0394499c (diff)
downloadlinux-3ea88d6738ebda95e05ada0c7b72f224d0a36953.tar.gz
Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/avi/kvm
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/avi/kvm: KVM: Prevent guest fpu state from leaking into the host
-rw-r--r--drivers/kvm/kvm.h3
-rw-r--r--drivers/kvm/kvm_main.c22
-rw-r--r--drivers/kvm/vmx.c12
3 files changed, 28 insertions, 9 deletions
diff --git a/drivers/kvm/kvm.h b/drivers/kvm/kvm.h
index 1c040d80c64..152312c1faf 100644
--- a/drivers/kvm/kvm.h
+++ b/drivers/kvm/kvm.h
@@ -304,6 +304,7 @@ struct kvm_vcpu {
char *host_fx_image;
char *guest_fx_image;
int fpu_active;
+ int guest_fpu_loaded;
int mmio_needed;
int mmio_read_completed;
@@ -508,6 +509,8 @@ void fx_init(struct kvm_vcpu *vcpu);
void load_msrs(struct vmx_msr_entry *e, int n);
void save_msrs(struct vmx_msr_entry *e, int n);
void kvm_resched(struct kvm_vcpu *vcpu);
+void kvm_load_guest_fpu(struct kvm_vcpu *vcpu);
+void kvm_put_guest_fpu(struct kvm_vcpu *vcpu);
int kvm_read_guest(struct kvm_vcpu *vcpu,
gva_t addr,
diff --git a/drivers/kvm/kvm_main.c b/drivers/kvm/kvm_main.c
index da985b31b17..8f1f07adb04 100644
--- a/drivers/kvm/kvm_main.c
+++ b/drivers/kvm/kvm_main.c
@@ -253,6 +253,28 @@ int kvm_write_guest(struct kvm_vcpu *vcpu, gva_t addr, unsigned long size,
}
EXPORT_SYMBOL_GPL(kvm_write_guest);
+void kvm_load_guest_fpu(struct kvm_vcpu *vcpu)
+{
+ if (!vcpu->fpu_active || vcpu->guest_fpu_loaded)
+ return;
+
+ vcpu->guest_fpu_loaded = 1;
+ fx_save(vcpu->host_fx_image);
+ fx_restore(vcpu->guest_fx_image);
+}
+EXPORT_SYMBOL_GPL(kvm_load_guest_fpu);
+
+void kvm_put_guest_fpu(struct kvm_vcpu *vcpu)
+{
+ if (!vcpu->guest_fpu_loaded)
+ return;
+
+ vcpu->guest_fpu_loaded = 0;
+ fx_save(vcpu->guest_fx_image);
+ fx_restore(vcpu->host_fx_image);
+}
+EXPORT_SYMBOL_GPL(kvm_put_guest_fpu);
+
/*
* Switches to specified vcpu, until a matching vcpu_put()
*/
diff --git a/drivers/kvm/vmx.c b/drivers/kvm/vmx.c
index 184238e2ece..c1ac106ace8 100644
--- a/drivers/kvm/vmx.c
+++ b/drivers/kvm/vmx.c
@@ -280,6 +280,7 @@ static void vmx_vcpu_load(struct kvm_vcpu *vcpu)
static void vmx_vcpu_put(struct kvm_vcpu *vcpu)
{
+ kvm_put_guest_fpu(vcpu);
put_cpu();
}
@@ -1847,10 +1848,8 @@ again:
if (vcpu->guest_debug.enabled)
kvm_guest_debug_pre(vcpu);
- if (vcpu->fpu_active) {
- fx_save(vcpu->host_fx_image);
- fx_restore(vcpu->guest_fx_image);
- }
+ kvm_load_guest_fpu(vcpu);
+
/*
* Loading guest fpu may have cleared host cr0.ts
*/
@@ -2012,11 +2011,6 @@ again:
}
#endif
- if (vcpu->fpu_active) {
- fx_save(vcpu->guest_fx_image);
- fx_restore(vcpu->host_fx_image);
- }
-
vcpu->interrupt_window_open = (vmcs_read32(GUEST_INTERRUPTIBILITY_INFO) & 3) == 0;
asm ("mov %0, %%ds; mov %0, %%es" : : "r"(__USER_DS));