From: Jan Kiszka <[email protected]> So far user space was not able to save and restore debug registers for migration or after reset. Plug this hole.
Signed-off-by: Jan Kiszka <[email protected]> Signed-off-by: Avi Kivity <[email protected]> diff --git a/Documentation/kvm/api.txt b/Documentation/kvm/api.txt index 9e5de5a..d170cb4 100644 --- a/Documentation/kvm/api.txt +++ b/Documentation/kvm/api.txt @@ -718,6 +718,37 @@ If KVM_CAP_INTR_SHADOW is available, KVM_VCPUEVENT_VALID_SHADOW can be set in the flags field to signal that interrupt.shadow contains a valid state and shall be written into the VCPU. +4.32 KVM_GET_DEBUGREGS + +Capability: KVM_CAP_DEBUGREGS +Architectures: x86 +Type: vm ioctl +Parameters: struct kvm_debugregs (out) +Returns: 0 on success, -1 on error + +Reads debug registers from the vcpu. + +struct kvm_debugregs { + __u64 db[4]; + __u64 dr6; + __u64 dr7; + __u64 flags; + __u64 reserved[9]; +}; + +4.33 KVM_SET_DEBUGREGS + +Capability: KVM_CAP_DEBUGREGS +Architectures: x86 +Type: vm ioctl +Parameters: struct kvm_debugregs (in) +Returns: 0 on success, -1 on error + +Writes debug registers into the vcpu. + +See KVM_GET_DEBUGREGS for the data structure. The flags field is unused +yet and must be cleared on entry. + 5. The kvm_run structure diff --git a/arch/x86/include/asm/kvm.h b/arch/x86/include/asm/kvm.h index fb61170..ff90055 100644 --- a/arch/x86/include/asm/kvm.h +++ b/arch/x86/include/asm/kvm.h @@ -21,6 +21,7 @@ #define __KVM_HAVE_PIT_STATE2 #define __KVM_HAVE_XEN_HVM #define __KVM_HAVE_VCPU_EVENTS +#define __KVM_HAVE_DEBUGREGS /* Architectural interrupt line count. */ #define KVM_NR_INTERRUPTS 256 @@ -289,4 +290,13 @@ struct kvm_vcpu_events { __u32 reserved[10]; }; +/* for KVM_GET/SET_DEBUGREGS */ +struct kvm_debugregs { + __u64 db[4]; + __u64 dr6; + __u64 dr7; + __u64 flags; + __u64 reserved[9]; +}; + #endif /* _ASM_X86_KVM_H */ diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index fa05b24..e25a522 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -1570,6 +1570,7 @@ int kvm_dev_ioctl_check_extension(long ext) case KVM_CAP_HYPERV_VAPIC: case KVM_CAP_HYPERV_SPIN: case KVM_CAP_PCI_SEGMENT: + case KVM_CAP_DEBUGREGS: r = 1; break; case KVM_CAP_COALESCED_MMIO: @@ -2186,6 +2187,36 @@ static int kvm_vcpu_ioctl_x86_set_vcpu_events(struct kvm_vcpu *vcpu, return 0; } +static void kvm_vcpu_ioctl_x86_get_debugregs(struct kvm_vcpu *vcpu, + struct kvm_debugregs *dbgregs) +{ + vcpu_load(vcpu); + + memcpy(dbgregs->db, vcpu->arch.db, sizeof(vcpu->arch.db)); + dbgregs->dr6 = vcpu->arch.dr6; + dbgregs->dr7 = vcpu->arch.dr7; + dbgregs->flags = 0; + + vcpu_put(vcpu); +} + +static int kvm_vcpu_ioctl_x86_set_debugregs(struct kvm_vcpu *vcpu, + struct kvm_debugregs *dbgregs) +{ + if (dbgregs->flags) + return -EINVAL; + + vcpu_load(vcpu); + + memcpy(vcpu->arch.db, dbgregs->db, sizeof(vcpu->arch.db)); + vcpu->arch.dr6 = dbgregs->dr6; + vcpu->arch.dr7 = dbgregs->dr7; + + vcpu_put(vcpu); + + return 0; +} + long kvm_arch_vcpu_ioctl(struct file *filp, unsigned int ioctl, unsigned long arg) { @@ -2364,6 +2395,29 @@ long kvm_arch_vcpu_ioctl(struct file *filp, r = kvm_vcpu_ioctl_x86_set_vcpu_events(vcpu, &events); break; } + case KVM_GET_DEBUGREGS: { + struct kvm_debugregs dbgregs; + + kvm_vcpu_ioctl_x86_get_debugregs(vcpu, &dbgregs); + + r = -EFAULT; + if (copy_to_user(argp, &dbgregs, + sizeof(struct kvm_debugregs))) + break; + r = 0; + break; + } + case KVM_SET_DEBUGREGS: { + struct kvm_debugregs dbgregs; + + r = -EFAULT; + if (copy_from_user(&dbgregs, argp, + sizeof(struct kvm_debugregs))) + break; + + r = kvm_vcpu_ioctl_x86_set_debugregs(vcpu, &dbgregs); + break; + } default: r = -EINVAL; } diff --git a/include/linux/kvm.h b/include/linux/kvm.h index b131022..d25912e 100644 --- a/include/linux/kvm.h +++ b/include/linux/kvm.h @@ -503,6 +503,9 @@ struct kvm_ioeventfd { #define KVM_CAP_PCI_SEGMENT 47 #define KVM_CAP_PPC_PAIRED_SINGLES 48 #define KVM_CAP_INTR_SHADOW 49 +#ifdef __KVM_HAVE_DEBUGREGS +#define KVM_CAP_DEBUGREGS 50 +#endif #ifdef KVM_CAP_IRQ_ROUTING @@ -689,6 +692,9 @@ struct kvm_clock_data { /* Available with KVM_CAP_VCPU_EVENTS */ #define KVM_GET_VCPU_EVENTS _IOR(KVMIO, 0x9f, struct kvm_vcpu_events) #define KVM_SET_VCPU_EVENTS _IOW(KVMIO, 0xa0, struct kvm_vcpu_events) +/* Available with KVM_CAP_DEBUGREGS */ +#define KVM_GET_DEBUGREGS _IOR(KVMIO, 0xa1, struct kvm_debugregs) +#define KVM_SET_DEBUGREGS _IOW(KVMIO, 0xa2, struct kvm_debugregs) #define KVM_DEV_ASSIGN_ENABLE_IOMMU (1 << 0) -- To unsubscribe from this list: send the line "unsubscribe kvm-commits" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
