From 2d5b5a665508c60577c1088e0405850a965b6795 Mon Sep 17 00:00:00 2001 From: Sheng Yang Date: Sun, 13 Jun 2010 17:29:39 +0800 Subject: [PATCH] KVM: x86: XSAVE/XRSTOR live migration support This patch enable save/restore of xsave state. Signed-off-by: Sheng Yang Signed-off-by: Marcelo Tosatti --- Documentation/kvm/api.txt | 74 +++++++++++++++++++ arch/x86/include/asm/kvm.h | 22 ++++++ arch/x86/include/asm/xsave.h | 7 +- arch/x86/kvm/x86.c | 139 +++++++++++++++++++++++++++++++++++ include/linux/kvm.h | 12 +++ 5 files changed, 252 insertions(+), 2 deletions(-) diff --git a/Documentation/kvm/api.txt b/Documentation/kvm/api.txt index 159b4efe1b0e..ffba03f55bdf 100644 --- a/Documentation/kvm/api.txt +++ b/Documentation/kvm/api.txt @@ -922,6 +922,80 @@ Define which vcpu is the Bootstrap Processor (BSP). Values are the same as the vcpu id in KVM_CREATE_VCPU. If this ioctl is not called, the default is vcpu 0. +4.41 KVM_GET_XSAVE + +Capability: KVM_CAP_XSAVE +Architectures: x86 +Type: vcpu ioctl +Parameters: struct kvm_xsave (out) +Returns: 0 on success, -1 on error + +struct kvm_xsave { + __u32 region[1024]; +}; + +This ioctl would copy current vcpu's xsave struct to the userspace. + +4.42 KVM_SET_XSAVE + +Capability: KVM_CAP_XSAVE +Architectures: x86 +Type: vcpu ioctl +Parameters: struct kvm_xsave (in) +Returns: 0 on success, -1 on error + +struct kvm_xsave { + __u32 region[1024]; +}; + +This ioctl would copy userspace's xsave struct to the kernel. + +4.43 KVM_GET_XCRS + +Capability: KVM_CAP_XCRS +Architectures: x86 +Type: vcpu ioctl +Parameters: struct kvm_xcrs (out) +Returns: 0 on success, -1 on error + +struct kvm_xcr { + __u32 xcr; + __u32 reserved; + __u64 value; +}; + +struct kvm_xcrs { + __u32 nr_xcrs; + __u32 flags; + struct kvm_xcr xcrs[KVM_MAX_XCRS]; + __u64 padding[16]; +}; + +This ioctl would copy current vcpu's xcrs to the userspace. + +4.44 KVM_SET_XCRS + +Capability: KVM_CAP_XCRS +Architectures: x86 +Type: vcpu ioctl +Parameters: struct kvm_xcrs (in) +Returns: 0 on success, -1 on error + +struct kvm_xcr { + __u32 xcr; + __u32 reserved; + __u64 value; +}; + +struct kvm_xcrs { + __u32 nr_xcrs; + __u32 flags; + struct kvm_xcr xcrs[KVM_MAX_XCRS]; + __u64 padding[16]; +}; + +This ioctl would set vcpu's xcr to the value userspace specified. + 5. The kvm_run structure Application code obtains a pointer to the kvm_run structure by diff --git a/arch/x86/include/asm/kvm.h b/arch/x86/include/asm/kvm.h index ff90055c7f0b..4d8dcbdfc120 100644 --- a/arch/x86/include/asm/kvm.h +++ b/arch/x86/include/asm/kvm.h @@ -22,6 +22,8 @@ #define __KVM_HAVE_XEN_HVM #define __KVM_HAVE_VCPU_EVENTS #define __KVM_HAVE_DEBUGREGS +#define __KVM_HAVE_XSAVE +#define __KVM_HAVE_XCRS /* Architectural interrupt line count. */ #define KVM_NR_INTERRUPTS 256 @@ -299,4 +301,24 @@ struct kvm_debugregs { __u64 reserved[9]; }; +/* for KVM_CAP_XSAVE */ +struct kvm_xsave { + __u32 region[1024]; +}; + +#define KVM_MAX_XCRS 16 + +struct kvm_xcr { + __u32 xcr; + __u32 reserved; + __u64 value; +}; + +struct kvm_xcrs { + __u32 nr_xcrs; + __u32 flags; + struct kvm_xcr xcrs[KVM_MAX_XCRS]; + __u64 padding[16]; +}; + #endif /* _ASM_X86_KVM_H */ diff --git a/arch/x86/include/asm/xsave.h b/arch/x86/include/asm/xsave.h index 29ee4e4c64cf..32c36668fa7b 100644 --- a/arch/x86/include/asm/xsave.h +++ b/arch/x86/include/asm/xsave.h @@ -13,8 +13,11 @@ #define FXSAVE_SIZE 512 -#define XSTATE_YMM_SIZE 256 -#define XSTATE_YMM_OFFSET (512 + 64) +#define XSAVE_HDR_SIZE 64 +#define XSAVE_HDR_OFFSET FXSAVE_SIZE + +#define XSAVE_YMM_SIZE 256 +#define XSAVE_YMM_OFFSET (XSAVE_HDR_SIZE + XSAVE_HDR_OFFSET) /* * These are the features that the OS can handle currently. diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index 795999e1ac19..0c8dc9614e7d 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -1680,6 +1680,7 @@ int kvm_dev_ioctl_check_extension(long ext) 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 @@ int kvm_dev_ioctl_check_extension(long ext) 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 @@ static int kvm_vcpu_ioctl_x86_set_debugregs(struct kvm_vcpu *vcpu, 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 @@ long kvm_arch_vcpu_ioctl(struct file *filp, 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; } diff --git a/include/linux/kvm.h b/include/linux/kvm.h index 23ea02253900..6fd40f540a8e 100644 --- a/include/linux/kvm.h +++ b/include/linux/kvm.h @@ -524,6 +524,12 @@ struct kvm_enable_cap { #define KVM_CAP_PPC_OSI 52 #define KVM_CAP_PPC_UNSET_IRQ 53 #define KVM_CAP_ENABLE_CAP 54 +#ifdef __KVM_HAVE_XSAVE +#define KVM_CAP_XSAVE 55 +#endif +#ifdef __KVM_HAVE_XCRS +#define KVM_CAP_XCRS 56 +#endif #ifdef KVM_CAP_IRQ_ROUTING @@ -714,6 +720,12 @@ struct kvm_clock_data { #define KVM_GET_DEBUGREGS _IOR(KVMIO, 0xa1, struct kvm_debugregs) #define KVM_SET_DEBUGREGS _IOW(KVMIO, 0xa2, struct kvm_debugregs) #define KVM_ENABLE_CAP _IOW(KVMIO, 0xa3, struct kvm_enable_cap) +/* Available with KVM_CAP_XSAVE */ +#define KVM_GET_XSAVE _IOR(KVMIO, 0xa4, struct kvm_xsave) +#define KVM_SET_XSAVE _IOW(KVMIO, 0xa5, struct kvm_xsave) +/* Available with KVM_CAP_XCRS */ +#define KVM_GET_XCRS _IOR(KVMIO, 0xa6, struct kvm_xcrs) +#define KVM_SET_XCRS _IOW(KVMIO, 0xa7, struct kvm_xcrs) #define KVM_DEV_ASSIGN_ENABLE_IOMMU (1 << 0) -- 2.39.2