From b8836737d92c139be770eae3d6574e33d1224caf Mon Sep 17 00:00:00 2001 From: Avi Kivity Date: Sun, 1 Apr 2007 16:34:31 +0300 Subject: [PATCH] KVM: Add fpu get/set operations These are really helpful when migrating an floating point app to another machine. Signed-off-by: Avi Kivity --- drivers/kvm/kvm_main.c | 86 ++++++++++++++++++++++++++++++++++++++++++ include/linux/kvm.h | 17 +++++++++ 2 files changed, 103 insertions(+) diff --git a/drivers/kvm/kvm_main.c b/drivers/kvm/kvm_main.c index e495855727..b065c49915 100644 --- a/drivers/kvm/kvm_main.c +++ b/drivers/kvm/kvm_main.c @@ -2398,6 +2398,67 @@ static int kvm_vcpu_ioctl_set_sigmask(struct kvm_vcpu *vcpu, sigset_t *sigset) return 0; } +/* + * fxsave fpu state. Taken from x86_64/processor.h. To be killed when + * we have asm/x86/processor.h + */ +struct fxsave { + u16 cwd; + u16 swd; + u16 twd; + u16 fop; + u64 rip; + u64 rdp; + u32 mxcsr; + u32 mxcsr_mask; + u32 st_space[32]; /* 8*16 bytes for each FP-reg = 128 bytes */ +#ifdef CONFIG_X86_64 + u32 xmm_space[64]; /* 16*16 bytes for each XMM-reg = 256 bytes */ +#else + u32 xmm_space[32]; /* 8*16 bytes for each XMM-reg = 128 bytes */ +#endif +}; + +static int kvm_vcpu_ioctl_get_fpu(struct kvm_vcpu *vcpu, struct kvm_fpu *fpu) +{ + struct fxsave *fxsave = (struct fxsave *)vcpu->guest_fx_image; + + vcpu_load(vcpu); + + memcpy(fpu->fpr, fxsave->st_space, 128); + fpu->fcw = fxsave->cwd; + fpu->fsw = fxsave->swd; + fpu->ftwx = fxsave->twd; + fpu->last_opcode = fxsave->fop; + fpu->last_ip = fxsave->rip; + fpu->last_dp = fxsave->rdp; + memcpy(fpu->xmm, fxsave->xmm_space, sizeof fxsave->xmm_space); + + vcpu_put(vcpu); + + return 0; +} + +static int kvm_vcpu_ioctl_set_fpu(struct kvm_vcpu *vcpu, struct kvm_fpu *fpu) +{ + struct fxsave *fxsave = (struct fxsave *)vcpu->guest_fx_image; + + vcpu_load(vcpu); + + memcpy(fxsave->st_space, fpu->fpr, 128); + fxsave->cwd = fpu->fcw; + fxsave->swd = fpu->fsw; + fxsave->twd = fpu->ftwx; + fxsave->fop = fpu->last_opcode; + fxsave->rip = fpu->last_ip; + fxsave->rdp = fpu->last_dp; + memcpy(fxsave->xmm_space, fpu->xmm, sizeof fxsave->xmm_space); + + vcpu_put(vcpu); + + return 0; +} + static long kvm_vcpu_ioctl(struct file *filp, unsigned int ioctl, unsigned long arg) { @@ -2542,6 +2603,31 @@ static long kvm_vcpu_ioctl(struct file *filp, r = kvm_vcpu_ioctl_set_sigmask(vcpu, &sigset); break; } + case KVM_GET_FPU: { + struct kvm_fpu fpu; + + memset(&fpu, 0, sizeof fpu); + r = kvm_vcpu_ioctl_get_fpu(vcpu, &fpu); + if (r) + goto out; + r = -EFAULT; + if (copy_to_user(argp, &fpu, sizeof fpu)) + goto out; + r = 0; + break; + } + case KVM_SET_FPU: { + struct kvm_fpu fpu; + + r = -EFAULT; + if (copy_from_user(&fpu, argp, sizeof fpu)) + goto out; + r = kvm_vcpu_ioctl_set_fpu(vcpu, &fpu); + if (r) + goto out; + r = 0; + break; + } default: ; } diff --git a/include/linux/kvm.h b/include/linux/kvm.h index da9b23fa4b..07bf353eeb 100644 --- a/include/linux/kvm.h +++ b/include/linux/kvm.h @@ -126,6 +126,21 @@ struct kvm_regs { __u64 rip, rflags; }; +/* for KVM_GET_FPU and KVM_SET_FPU */ +struct kvm_fpu { + __u8 fpr[8][16]; + __u16 fcw; + __u16 fsw; + __u8 ftwx; /* in fxsave format */ + __u8 pad1; + __u16 last_opcode; + __u64 last_ip; + __u64 last_dp; + __u8 xmm[16][16]; + __u32 mxcsr; + __u32 pad2; +}; + struct kvm_segment { __u64 base; __u32 limit; @@ -285,5 +300,7 @@ struct kvm_signal_mask { #define KVM_SET_MSRS _IOW(KVMIO, 0x89, struct kvm_msrs) #define KVM_SET_CPUID _IOW(KVMIO, 0x8a, struct kvm_cpuid) #define KVM_SET_SIGNAL_MASK _IOW(KVMIO, 0x8b, struct kvm_signal_mask) +#define KVM_GET_FPU _IOR(KVMIO, 0x8c, struct kvm_fpu) +#define KVM_SET_FPU _IOW(KVMIO, 0x8d, struct kvm_fpu) #endif -- 2.39.5