Gitweb:     
http://git.kernel.org/git/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=7702fd1f6fea57921f2e643d27a23a2d0394499c
Commit:     7702fd1f6fea57921f2e643d27a23a2d0394499c
Parent:     22b1a9203ea634ac0ee5240e021613da3328275f
Author:     Avi Kivity <[EMAIL PROTECTED]>
AuthorDate: Thu Jun 14 16:27:40 2007 +0300
Committer:  Avi Kivity <[EMAIL PROTECTED]>
CommitDate: Fri Jun 15 12:30:59 2007 +0300

    KVM: Prevent guest fpu state from leaking into the host
    
    The lazy fpu changes did not take into account that some vmexit handlers
    can sleep.  Move loading the guest state into the inner loop so that it
    can be reloaded if necessary, and move loading the host state into
    vmx_vcpu_put() so it can be performed whenever we relinquish the vcpu.
    
    Signed-off-by: Avi Kivity <[EMAIL PROTECTED]>
---
 drivers/kvm/kvm.h      |    3 +++
 drivers/kvm/kvm_main.c |   22 ++++++++++++++++++++++
 drivers/kvm/vmx.c      |   12 +++---------
 3 files changed, 28 insertions(+), 9 deletions(-)

diff --git a/drivers/kvm/kvm.h b/drivers/kvm/kvm.h
index 1c040d8..152312c 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 da985b3..8f1f07a 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 184238e..c1ac106 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));
-
To unsubscribe from this list: send the line "unsubscribe git-commits-head" in
the body of a message to [EMAIL PROTECTED]
More majordomo info at  http://vger.kernel.org/majordomo-info.html

Reply via email to