Commit 3ea88d67 authored by Linus Torvalds's avatar Linus Torvalds
Browse files

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
parents 4ff4275b 7702fd1f

drivers/kvm/kvm.h

+3 −0
Original line number Diff line number Diff line
@@ -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,

drivers/kvm/kvm_main.c

+22 −0
Original line number Diff line number Diff line
@@ -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()

 */

drivers/kvm/vmx.c

+3 −9
Original line number Diff line number Diff line
@@ -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 @@ static int vmx_vcpu_run(struct kvm_vcpu *vcpu, struct kvm_run *kvm_run) 
	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 @@ static int vmx_vcpu_run(struct kvm_vcpu *vcpu, struct kvm_run *kvm_run) 
	}

#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));