KVM: x86: XSAVE/XRSTOR live migration support
This patch enable save/restore of xsave state.
Signed-off-by: Sheng Yang <sheng@linux.intel.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 795999e..0c8dc96 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -1680,6 +1680,7 @@
case KVM_CAP_PCI_SEGMENT:
case KVM_CAP_DEBUGREGS:
case KVM_CAP_X86_ROBUST_SINGLESTEP:
+ case KVM_CAP_XSAVE:
r = 1;
break;
case KVM_CAP_COALESCED_MMIO:
@@ -1703,6 +1704,9 @@
case KVM_CAP_MCE:
r = KVM_MAX_MCE_BANKS;
break;
+ case KVM_CAP_XCRS:
+ r = cpu_has_xsave;
+ break;
default:
r = 0;
break;
@@ -2355,6 +2359,77 @@
return 0;
}
+static void kvm_vcpu_ioctl_x86_get_xsave(struct kvm_vcpu *vcpu,
+ struct kvm_xsave *guest_xsave)
+{
+ if (cpu_has_xsave)
+ memcpy(guest_xsave->region,
+ &vcpu->arch.guest_fpu.state->xsave,
+ sizeof(struct xsave_struct));
+ else {
+ memcpy(guest_xsave->region,
+ &vcpu->arch.guest_fpu.state->fxsave,
+ sizeof(struct i387_fxsave_struct));
+ *(u64 *)&guest_xsave->region[XSAVE_HDR_OFFSET / sizeof(u32)] =
+ XSTATE_FPSSE;
+ }
+}
+
+static int kvm_vcpu_ioctl_x86_set_xsave(struct kvm_vcpu *vcpu,
+ struct kvm_xsave *guest_xsave)
+{
+ u64 xstate_bv =
+ *(u64 *)&guest_xsave->region[XSAVE_HDR_OFFSET / sizeof(u32)];
+
+ if (cpu_has_xsave)
+ memcpy(&vcpu->arch.guest_fpu.state->xsave,
+ guest_xsave->region, sizeof(struct xsave_struct));
+ else {
+ if (xstate_bv & ~XSTATE_FPSSE)
+ return -EINVAL;
+ memcpy(&vcpu->arch.guest_fpu.state->fxsave,
+ guest_xsave->region, sizeof(struct i387_fxsave_struct));
+ }
+ return 0;
+}
+
+static void kvm_vcpu_ioctl_x86_get_xcrs(struct kvm_vcpu *vcpu,
+ struct kvm_xcrs *guest_xcrs)
+{
+ if (!cpu_has_xsave) {
+ guest_xcrs->nr_xcrs = 0;
+ return;
+ }
+
+ guest_xcrs->nr_xcrs = 1;
+ guest_xcrs->flags = 0;
+ guest_xcrs->xcrs[0].xcr = XCR_XFEATURE_ENABLED_MASK;
+ guest_xcrs->xcrs[0].value = vcpu->arch.xcr0;
+}
+
+static int kvm_vcpu_ioctl_x86_set_xcrs(struct kvm_vcpu *vcpu,
+ struct kvm_xcrs *guest_xcrs)
+{
+ int i, r = 0;
+
+ if (!cpu_has_xsave)
+ return -EINVAL;
+
+ if (guest_xcrs->nr_xcrs > KVM_MAX_XCRS || guest_xcrs->flags)
+ return -EINVAL;
+
+ for (i = 0; i < guest_xcrs->nr_xcrs; i++)
+ /* Only support XCR0 currently */
+ if (guest_xcrs->xcrs[0].xcr == XCR_XFEATURE_ENABLED_MASK) {
+ r = __kvm_set_xcr(vcpu, XCR_XFEATURE_ENABLED_MASK,
+ guest_xcrs->xcrs[0].value);
+ break;
+ }
+ if (r)
+ r = -EINVAL;
+ return r;
+}
+
long kvm_arch_vcpu_ioctl(struct file *filp,
unsigned int ioctl, unsigned long arg)
{
@@ -2556,6 +2631,70 @@
r = kvm_vcpu_ioctl_x86_set_debugregs(vcpu, &dbgregs);
break;
}
+ case KVM_GET_XSAVE: {
+ struct kvm_xsave *xsave;
+
+ xsave = kzalloc(sizeof(struct kvm_xsave), GFP_KERNEL);
+ r = -ENOMEM;
+ if (!xsave)
+ break;
+
+ kvm_vcpu_ioctl_x86_get_xsave(vcpu, xsave);
+
+ r = -EFAULT;
+ if (copy_to_user(argp, xsave, sizeof(struct kvm_xsave)))
+ break;
+ r = 0;
+ break;
+ }
+ case KVM_SET_XSAVE: {
+ struct kvm_xsave *xsave;
+
+ xsave = kzalloc(sizeof(struct kvm_xsave), GFP_KERNEL);
+ r = -ENOMEM;
+ if (!xsave)
+ break;
+
+ r = -EFAULT;
+ if (copy_from_user(xsave, argp, sizeof(struct kvm_xsave)))
+ break;
+
+ r = kvm_vcpu_ioctl_x86_set_xsave(vcpu, xsave);
+ break;
+ }
+ case KVM_GET_XCRS: {
+ struct kvm_xcrs *xcrs;
+
+ xcrs = kzalloc(sizeof(struct kvm_xcrs), GFP_KERNEL);
+ r = -ENOMEM;
+ if (!xcrs)
+ break;
+
+ kvm_vcpu_ioctl_x86_get_xcrs(vcpu, xcrs);
+
+ r = -EFAULT;
+ if (copy_to_user(argp, xcrs,
+ sizeof(struct kvm_xcrs)))
+ break;
+ r = 0;
+ break;
+ }
+ case KVM_SET_XCRS: {
+ struct kvm_xcrs *xcrs;
+
+ xcrs = kzalloc(sizeof(struct kvm_xcrs), GFP_KERNEL);
+ r = -ENOMEM;
+ if (!xcrs)
+ break;
+
+ r = -EFAULT;
+ if (copy_from_user(xcrs, argp,
+ sizeof(struct kvm_xcrs)))
+ break;
+
+ r = kvm_vcpu_ioctl_x86_set_xcrs(vcpu, xcrs);
+ break;
+ }
default:
r = -EINVAL;
}