From: Mihai Donțu <[email protected]> This event is sent when the extended control register XCR0 is going to be changed.
Signed-off-by: Mihai Donțu <[email protected]> Co-developed-by: Nicușor Cîțu <[email protected]> Signed-off-by: Nicușor Cîțu <[email protected]> Signed-off-by: Adalbert Lazăr <[email protected]> --- Documentation/virt/kvm/kvmi.rst | 25 ++++++ arch/x86/include/asm/kvmi_host.h | 2 + arch/x86/kvm/kvmi.c | 39 +++++++++ arch/x86/kvm/x86.c | 6 ++ include/uapi/linux/kvmi.h | 1 + .../testing/selftests/kvm/x86_64/kvmi_test.c | 83 +++++++++++++++++++ virt/kvm/introspection/kvmi.c | 1 + 7 files changed, 157 insertions(+) diff --git a/Documentation/virt/kvm/kvmi.rst b/Documentation/virt/kvm/kvmi.rst index 1c5e256975fe..06ed05f4791b 100644 --- a/Documentation/virt/kvm/kvmi.rst +++ b/Documentation/virt/kvm/kvmi.rst @@ -549,6 +549,7 @@ the following events:: KVMI_EVENT_BREAKPOINT KVMI_EVENT_CR KVMI_EVENT_HYPERCALL + KVMI_EVENT_XSETBV When an event is enabled, the introspection tool is notified and must reply with: continue, retry, crash, etc. (see **Events** below). @@ -1019,3 +1020,27 @@ other vCPU introspection event. (``error_code``) and CR2 are sent to the introspection tool, which should check if its exception has been injected or overridden. +7. KVMI_EVENT_XSETBV +-------------------- + +:Architectures: x86 +:Versions: >= 1 +:Actions: CONTINUE, CRASH +:Parameters: + +:: + + struct kvmi_event; + +:Returns: + +:: + + struct kvmi_vcpu_hdr; + struct kvmi_event_reply; + +This event is sent when the extended control register XCR0 is going +to be changed and the introspection has been enabled for this event +(see *KVMI_VCPU_CONTROL_EVENTS*). + +``kvmi_event`` is sent to the introspection tool. diff --git a/arch/x86/include/asm/kvmi_host.h b/arch/x86/include/asm/kvmi_host.h index 24f3f8fdee62..b3fa950362db 100644 --- a/arch/x86/include/asm/kvmi_host.h +++ b/arch/x86/include/asm/kvmi_host.h @@ -30,6 +30,7 @@ bool kvmi_cr_event(struct kvm_vcpu *vcpu, unsigned int cr, unsigned long old_value, unsigned long *new_value); bool kvmi_cr3_intercepted(struct kvm_vcpu *vcpu); bool kvmi_monitor_cr3w_intercept(struct kvm_vcpu *vcpu, bool enable); +void kvmi_xsetbv_event(struct kvm_vcpu *vcpu); #else /* CONFIG_KVM_INTROSPECTION */ @@ -41,6 +42,7 @@ static inline bool kvmi_cr_event(struct kvm_vcpu *vcpu, unsigned int cr, static inline bool kvmi_cr3_intercepted(struct kvm_vcpu *vcpu) { return false; } static inline bool kvmi_monitor_cr3w_intercept(struct kvm_vcpu *vcpu, bool enable) { return false; } +static inline void kvmi_xsetbv_event(struct kvm_vcpu *vcpu) { } #endif /* CONFIG_KVM_INTROSPECTION */ diff --git a/arch/x86/kvm/kvmi.c b/arch/x86/kvm/kvmi.c index 9f8ef8a1a306..f947f18e9d72 100644 --- a/arch/x86/kvm/kvmi.c +++ b/arch/x86/kvm/kvmi.c @@ -662,3 +662,42 @@ void kvmi_arch_trap_event(struct kvm_vcpu *vcpu) kvmi_handle_common_event_actions(vcpu->kvm, action, "TRAP"); } } + +static u32 kvmi_send_xsetbv(struct kvm_vcpu *vcpu) +{ + int err, action; + + err = kvmi_send_event(vcpu, KVMI_EVENT_XSETBV, NULL, 0, + NULL, 0, &action); + if (err) + return KVMI_EVENT_ACTION_CONTINUE; + + return action; +} + +static void __kvmi_xsetbv_event(struct kvm_vcpu *vcpu) +{ + u32 action; + + action = kvmi_send_xsetbv(vcpu); + switch (action) { + case KVMI_EVENT_ACTION_CONTINUE: + break; + default: + kvmi_handle_common_event_actions(vcpu->kvm, action, "XSETBV"); + } +} + +void kvmi_xsetbv_event(struct kvm_vcpu *vcpu) +{ + struct kvm_introspection *kvmi; + + kvmi = kvmi_get(vcpu->kvm); + if (!kvmi) + return; + + if (is_event_enabled(vcpu, KVMI_EVENT_XSETBV)) + __kvmi_xsetbv_event(vcpu); + + kvmi_put(vcpu->kvm); +} diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index 0e3704bed6c4..ab0ad3b6ebc2 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -865,6 +865,12 @@ static int __kvm_set_xcr(struct kvm_vcpu *vcpu, u32 index, u64 xcr) } vcpu->arch.xcr0 = xcr0; +#ifdef CONFIG_KVM_INTROSPECTION + if (index == 0 && xcr0 != old_xcr0) + kvmi_xsetbv_event(vcpu); +#endif /* CONFIG_KVM_INTROSPECTION */ + + if ((xcr0 ^ old_xcr0) & XFEATURE_MASK_EXTEND) kvm_update_cpuid(vcpu); return 0; diff --git a/include/uapi/linux/kvmi.h b/include/uapi/linux/kvmi.h index d33e8dae0084..ecf140ba3cab 100644 --- a/include/uapi/linux/kvmi.h +++ b/include/uapi/linux/kvmi.h @@ -46,6 +46,7 @@ enum { KVMI_EVENT_BREAKPOINT = 3, KVMI_EVENT_CR = 4, KVMI_EVENT_TRAP = 5, + KVMI_EVENT_XSETBV = 6, KVMI_NUM_EVENTS }; diff --git a/tools/testing/selftests/kvm/x86_64/kvmi_test.c b/tools/testing/selftests/kvm/x86_64/kvmi_test.c index 66766d112006..3a45834e9235 100644 --- a/tools/testing/selftests/kvm/x86_64/kvmi_test.c +++ b/tools/testing/selftests/kvm/x86_64/kvmi_test.c @@ -22,6 +22,8 @@ #define VCPU_ID 5 +#define X86_FEATURE_XSAVE (1<<26) + static int socket_pair[2]; #define Kvm_socket socket_pair[0] #define Userspace_socket socket_pair[1] @@ -54,6 +56,7 @@ enum { GUEST_TEST_BP, GUEST_TEST_CR, GUEST_TEST_HYPERCALL, + GUEST_TEST_XSETBV, }; #define GUEST_REQUEST_TEST() GUEST_SYNC(0) @@ -85,6 +88,45 @@ static void guest_hypercall_test(void) asm volatile(".byte 0x0f,0x01,0xc1"); } +/* from fpu/internal.h */ +static u64 xgetbv(u32 index) +{ + u32 eax, edx; + + asm volatile(".byte 0x0f,0x01,0xd0" /* xgetbv */ + : "=a" (eax), "=d" (edx) + : "c" (index)); + return eax + ((u64)edx << 32); +} + +/* from fpu/internal.h */ +static void xsetbv(u32 index, u64 value) +{ + u32 eax = value; + u32 edx = value >> 32; + + asm volatile(".byte 0x0f,0x01,0xd1" /* xsetbv */ + : : "a" (eax), "d" (edx), "c" (index)); +} + +static void guest_xsetbv_test(void) +{ + const int SSE_BIT = 1 << 1; + const int AVX_BIT = 1 << 2; + u64 xcr0; + + /* avoid #UD */ + set_cr4(get_cr4() | X86_CR4_OSXSAVE); + + xcr0 = xgetbv(0); + if (xcr0 & AVX_BIT) + xcr0 &= ~AVX_BIT; + else + xcr0 |= (AVX_BIT | SSE_BIT); + + xsetbv(0, xcr0); +} + static void guest_code(void) { while (true) { @@ -100,6 +142,9 @@ static void guest_code(void) case GUEST_TEST_HYPERCALL: guest_hypercall_test(); break; + case GUEST_TEST_XSETBV: + guest_xsetbv_test(); + break; } GUEST_SIGNAL_TEST_DONE(); } @@ -1243,6 +1288,43 @@ static void test_cmd_vm_get_max_gfn(void) DEBUG("max_gfn: 0x%llx\n", rpl.gfn); } +static void test_event_xsetbv(struct kvm_vm *vm) +{ + struct vcpu_worker_data data = { + .vm = vm, + .vcpu_id = VCPU_ID, + .test_id = GUEST_TEST_XSETBV, + }; + __u16 event_id = KVMI_EVENT_XSETBV; + struct kvm_cpuid_entry2 *entry; + struct vcpu_reply rpl = {}; + struct kvmi_msg_hdr hdr; + pthread_t vcpu_thread; + struct kvmi_event ev; + + entry = kvm_get_supported_cpuid_entry(1); + if (!(entry->ecx & X86_FEATURE_XSAVE)) { + DEBUG("XSAVE is not supported, ecx 0x%x, skipping xsetbv test\n", + entry->ecx); + return; + } + + enable_vcpu_event(vm, event_id); + + vcpu_thread = start_vcpu_worker(&data); + + receive_event(&hdr, &ev, sizeof(ev), event_id); + + DEBUG("XSETBV event, rip 0x%llx\n", ev.arch.regs.rip); + + reply_to_event(&hdr, &ev, KVMI_EVENT_ACTION_CONTINUE, + &rpl, sizeof(rpl)); + + stop_vcpu_worker(vcpu_thread, &data); + + disable_vcpu_event(vm, event_id); +} + static void test_introspection(struct kvm_vm *vm) { srandom(time(0)); @@ -1268,6 +1350,7 @@ static void test_introspection(struct kvm_vm *vm) test_cmd_vcpu_control_cr(vm); test_cmd_vcpu_inject_exception(vm); test_cmd_vm_get_max_gfn(); + test_event_xsetbv(vm); unhook_introspection(vm); } diff --git a/virt/kvm/introspection/kvmi.c b/virt/kvm/introspection/kvmi.c index 0f2cec7e9c90..d358686fce76 100644 --- a/virt/kvm/introspection/kvmi.c +++ b/virt/kvm/introspection/kvmi.c @@ -83,6 +83,7 @@ static void setup_known_events(void) set_bit(KVMI_EVENT_HYPERCALL, Kvmi_known_vcpu_events); set_bit(KVMI_EVENT_PAUSE_VCPU, Kvmi_known_vcpu_events); set_bit(KVMI_EVENT_TRAP, Kvmi_known_vcpu_events); + set_bit(KVMI_EVENT_XSETBV, Kvmi_known_vcpu_events); bitmap_or(Kvmi_known_events, Kvmi_known_vm_events, Kvmi_known_vcpu_events, KVMI_NUM_EVENTS); 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