Messages in this thread | | | Date | Fri, 10 Dec 2021 17:25:02 +0100 | Subject | Re: [PATCH 16/19] kvm: x86: Introduce KVM_{G|S}ET_XSAVE2 ioctl | From | Paolo Bonzini <> |
| |
On 12/8/21 01:03, Yang Zhong wrote: > From: Jing Liu <jing2.liu@intel.com> > > When dynamic XSTATE features are supported, the xsave states are > beyond 4KB. The current kvm_xsave structure and related > KVM_{G, S}ET_XSAVE only allows 4KB which is not enough for full > states. > > Introduce a new kvm_xsave2 structure and the corresponding > KVM_GET_XSAVE2 and KVM_SET_XSAVE2 ioctls so that userspace VMM > can get and set the full xsave states. > > Signed-off-by: Jing Liu <jing2.liu@intel.com> > Signed-off-by: Yang Zhong <yang.zhong@intel.com> > --- > arch/x86/include/uapi/asm/kvm.h | 6 ++++ > arch/x86/kvm/x86.c | 62 +++++++++++++++++++++++++++++++++ > include/uapi/linux/kvm.h | 7 +++- > 3 files changed, 74 insertions(+), 1 deletion(-) > > diff --git a/arch/x86/include/uapi/asm/kvm.h b/arch/x86/include/uapi/asm/kvm.h > index 5a776a08f78c..de42a51e20c3 100644 > --- a/arch/x86/include/uapi/asm/kvm.h > +++ b/arch/x86/include/uapi/asm/kvm.h > @@ -47,6 +47,7 @@ > #define __KVM_HAVE_VCPU_EVENTS > #define __KVM_HAVE_DEBUGREGS > #define __KVM_HAVE_XSAVE > +#define __KVM_HAVE_XSAVE2 > #define __KVM_HAVE_XCRS > #define __KVM_HAVE_READONLY_MEM > > @@ -378,6 +379,11 @@ struct kvm_xsave { > __u32 region[1024]; > }; > > +struct kvm_xsave2 { > + __u32 size; > + __u8 state[0]; > +}; > + > #define KVM_MAX_XCRS 16 > > struct kvm_xcr { > diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c > index 8b033c9241d6..d212f6d2d39a 100644 > --- a/arch/x86/kvm/x86.c > +++ b/arch/x86/kvm/x86.c > @@ -4216,6 +4216,7 @@ int kvm_vm_ioctl_check_extension(struct kvm *kvm, long ext) > case KVM_CAP_DEBUGREGS: > case KVM_CAP_X86_ROBUST_SINGLESTEP: > case KVM_CAP_XSAVE: > + case KVM_CAP_XSAVE2: > case KVM_CAP_ASYNC_PF: > case KVM_CAP_ASYNC_PF_INT: > case KVM_CAP_GET_TSC_KHZ: > @@ -4940,6 +4941,17 @@ static void kvm_vcpu_ioctl_x86_get_xsave(struct kvm_vcpu *vcpu, > vcpu->arch.pkru); > } > > +static void kvm_vcpu_ioctl_x86_get_xsave2(struct kvm_vcpu *vcpu, > + u8 *state, u32 size) > +{ > + if (fpstate_is_confidential(&vcpu->arch.guest_fpu)) > + return; > + > + fpu_copy_guest_fpstate_to_uabi(&vcpu->arch.guest_fpu, > + state, size, > + vcpu->arch.pkru); > +} > + > static int kvm_vcpu_ioctl_x86_set_xsave(struct kvm_vcpu *vcpu, > struct kvm_xsave *guest_xsave) > { > @@ -4951,6 +4963,15 @@ static int kvm_vcpu_ioctl_x86_set_xsave(struct kvm_vcpu *vcpu, > supported_xcr0, &vcpu->arch.pkru); > } > > +static int kvm_vcpu_ioctl_x86_set_xsave2(struct kvm_vcpu *vcpu, u8 *state) > +{ > + if (fpstate_is_confidential(&vcpu->arch.guest_fpu)) > + return 0; > + > + return fpu_copy_uabi_to_guest_fpstate(&vcpu->arch.guest_fpu, state, > + supported_xcr0, &vcpu->arch.pkru); > +} > + > static void kvm_vcpu_ioctl_x86_get_xcrs(struct kvm_vcpu *vcpu, > struct kvm_xcrs *guest_xcrs) > { > @@ -5416,6 +5437,47 @@ long kvm_arch_vcpu_ioctl(struct file *filp, > r = kvm_vcpu_ioctl_x86_set_xsave(vcpu, u.xsave); > break; > } > + case KVM_GET_XSAVE2: { > + struct kvm_xsave2 __user *xsave2_arg = argp; > + struct kvm_xsave2 xsave2; > + > + r = -EFAULT; > + if (copy_from_user(&xsave2, xsave2_arg, sizeof(struct kvm_xsave2))) > + break; > + > + u.buffer = kzalloc(xsave2.size, GFP_KERNEL_ACCOUNT); > + > + r = -ENOMEM; > + if (!u.buffer) > + break; > + > + kvm_vcpu_ioctl_x86_get_xsave2(vcpu, u.buffer, xsave2.size); > + > + r = -EFAULT; > + if (copy_to_user(xsave2_arg->state, u.buffer, xsave2.size)) > + break; > + > + r = 0; > + break; > + } > + case KVM_SET_XSAVE2: { > + struct kvm_xsave2 __user *xsave2_arg = argp; > + struct kvm_xsave2 xsave2; > + > + r = -EFAULT; > + if (copy_from_user(&xsave2, xsave2_arg, sizeof(struct kvm_xsave2))) > + break; > + > + u.buffer = memdup_user(xsave2_arg->state, xsave2.size); > + > + if (IS_ERR(u.buffer)) { > + r = PTR_ERR(u.buffer); > + goto out_nofree; > + } > + > + r = kvm_vcpu_ioctl_x86_set_xsave2(vcpu, u.buffer); > + break; > + } > case KVM_GET_XCRS: { > u.xcrs = kzalloc(sizeof(struct kvm_xcrs), GFP_KERNEL_ACCOUNT); > r = -ENOMEM; > diff --git a/include/uapi/linux/kvm.h b/include/uapi/linux/kvm.h > index 0c7b301c7254..603e1ca9ba09 100644 > --- a/include/uapi/linux/kvm.h > +++ b/include/uapi/linux/kvm.h > @@ -1132,7 +1132,9 @@ struct kvm_ppc_resize_hpt { > #define KVM_CAP_EXIT_ON_EMULATION_FAILURE 204 > #define KVM_CAP_ARM_MTE 205 > #define KVM_CAP_VM_MOVE_ENC_CONTEXT_FROM 206 > - > +#ifdef __KVM_HAVE_XSAVE2 > +#define KVM_CAP_XSAVE2 207 > +#endif > #ifdef KVM_CAP_IRQ_ROUTING > > struct kvm_irq_routing_irqchip { > @@ -1679,6 +1681,9 @@ struct kvm_xen_hvm_attr { > #define KVM_GET_SREGS2 _IOR(KVMIO, 0xcc, struct kvm_sregs2) > #define KVM_SET_SREGS2 _IOW(KVMIO, 0xcd, struct kvm_sregs2) > > +#define KVM_GET_XSAVE2 _IOR(KVMIO, 0xcf, struct kvm_xsave2) > +#define KVM_SET_XSAVE2 _IOW(KVMIO, 0xd0, struct kvm_xsave2) > + > struct kvm_xen_vcpu_attr { > __u16 type; > __u16 pad[3]; >
Please also modify KVM_GET/SET_XSAVE to fail with ENOSPC if the requested size is bigger than 4096.
Paolo
| |