From mboxrd@z Thu Jan 1 00:00:00 1970 From: =?UTF-8?q?Adalbert=20Laz=C4=83r?= Subject: [PATCH v9 68/84] KVM: introspection: add KVMI_EVENT_XSETBV Date: Wed, 22 Jul 2020 00:09:06 +0300 Message-ID: <20200721210922.7646-69-alazar@bitdefender.com> References: <20200721210922.7646-1-alazar@bitdefender.com> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Return-path: In-Reply-To: <20200721210922.7646-1-alazar@bitdefender.com> Sender: kvm-owner@vger.kernel.org To: kvm@vger.kernel.org Cc: virtualization@lists.linux-foundation.org, Paolo Bonzini , =?UTF-8?q?Mihai=20Don=C8=9Bu?= , =?UTF-8?q?Nicu=C8=99or=20C=C3=AE=C8=9Bu?= , =?UTF-8?q?Adalbert=20Laz=C4=83r?= List-Id: virtualization@lists.linuxfoundation.org From: Mihai Donțu This event is sent when an extended control register XCR is going to be changed. Signed-off-by: Mihai Donțu Co-developed-by: Nicușor Cîțu Signed-off-by: Nicușor Cîțu Signed-off-by: Adalbert Lazăr --- Documentation/virt/kvm/kvmi.rst | 33 ++++++++ arch/x86/include/asm/kvmi_host.h | 4 + arch/x86/include/uapi/asm/kvmi.h | 7 ++ arch/x86/kvm/kvmi.c | 48 +++++++++++ arch/x86/kvm/x86.c | 6 ++ include/uapi/linux/kvmi.h | 1 + .../testing/selftests/kvm/x86_64/kvmi_test.c | 84 +++++++++++++++++++ virt/kvm/introspection/kvmi.c | 1 + 8 files changed, 184 insertions(+) diff --git a/Documentation/virt/kvm/kvmi.rst b/Documentation/virt/kvm/kvmi.rst index 7da8efd18b89..283e9a2dfda1 100644 --- a/Documentation/virt/kvm/kvmi.rst +++ b/Documentation/virt/kvm/kvmi.rst @@ -552,6 +552,7 @@ 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). @@ -1053,3 +1054,35 @@ other vCPU introspection event. ``kvmi_event``, exception/interrupt number, exception code (``error_code``) and address 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; + struct kvmi_event_xsetbv { + __u8 xcr; + __u8 padding[7]; + __u64 old_value; + __u64 new_value; + }; + +:Returns: + +:: + + struct kvmi_vcpu_hdr; + struct kvmi_event_reply; + +This event is sent when the extended control register XCR is going +to be changed and the introspection has been enabled for this event +(see *KVMI_VCPU_CONTROL_EVENTS*). + +``kvmi_event``, the extended control register number, the old value and +the new value are sent to the introspection tool. diff --git a/arch/x86/include/asm/kvmi_host.h b/arch/x86/include/asm/kvmi_host.h index 44580f77e34e..aed8a4b88a68 100644 --- a/arch/x86/include/asm/kvmi_host.h +++ b/arch/x86/include/asm/kvmi_host.h @@ -33,6 +33,8 @@ 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, u8 xcr, + u64 old_value, u64 new_value); #else /* CONFIG_KVM_INTROSPECTION */ @@ -45,6 +47,8 @@ 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, u8 xcr, + u64 old_value, u64 new_value) { } #endif /* CONFIG_KVM_INTROSPECTION */ diff --git a/arch/x86/include/uapi/asm/kvmi.h b/arch/x86/include/uapi/asm/kvmi.h index 4c59c9fe6b00..2f69a4f5d2e0 100644 --- a/arch/x86/include/uapi/asm/kvmi.h +++ b/arch/x86/include/uapi/asm/kvmi.h @@ -83,4 +83,11 @@ struct kvmi_event_cr_reply { __u64 new_val; }; +struct kvmi_event_xsetbv { + __u8 xcr; + __u8 padding[7]; + __u64 old_value; + __u64 new_value; +}; + #endif /* _UAPI_ASM_X86_KVMI_H */ diff --git a/arch/x86/kvm/kvmi.c b/arch/x86/kvm/kvmi.c index 0c6ab136084f..55c5e290730c 100644 --- a/arch/x86/kvm/kvmi.c +++ b/arch/x86/kvm/kvmi.c @@ -672,3 +672,51 @@ void kvmi_arch_send_trap_event(struct kvm_vcpu *vcpu) kvmi_handle_common_event_actions(vcpu->kvm, action); } } + +static u32 kvmi_send_xsetbv(struct kvm_vcpu *vcpu, u8 xcr, u64 old_value, + u64 new_value) +{ + struct kvmi_event_xsetbv e; + int err, action; + + memset(&e, 0, sizeof(e)); + e.xcr = xcr; + e.old_value = old_value; + e.new_value = new_value; + + err = kvmi_send_event(vcpu, KVMI_EVENT_XSETBV, &e, sizeof(e), + NULL, 0, &action); + if (err) + return KVMI_EVENT_ACTION_CONTINUE; + + return action; +} + +static void __kvmi_xsetbv_event(struct kvm_vcpu *vcpu, u8 xcr, + u64 old_value, u64 new_value) +{ + u32 action; + + action = kvmi_send_xsetbv(vcpu, xcr, old_value, new_value); + switch (action) { + case KVMI_EVENT_ACTION_CONTINUE: + break; + default: + kvmi_handle_common_event_actions(vcpu->kvm, action); + } +} + +void kvmi_xsetbv_event(struct kvm_vcpu *vcpu, u8 xcr, + u64 old_value, u64 new_value) +{ + struct kvm_introspection *kvmi; + + kvmi = kvmi_get(vcpu->kvm); + if (!kvmi) + return; + + if (is_event_enabled(vcpu, KVMI_EVENT_XSETBV)) + __kvmi_xsetbv_event(vcpu, xcr, old_value, new_value); + + kvmi_put(vcpu->kvm); +} diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index af987ad1a174..c3557a11817f 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -919,6 +919,12 @@ 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, 0, old_xcr0, xcr0); +#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 2a4cc8c41465..348a9a551091 100644 --- a/include/uapi/linux/kvmi.h +++ b/include/uapi/linux/kvmi.h @@ -49,6 +49,7 @@ 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 105adf75a68d..0569185a7064 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) @@ -89,6 +92,45 @@ 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) { @@ -104,6 +146,9 @@ 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(); } @@ -1431,6 +1476,44 @@ static void test_cmd_vm_get_max_gfn(void) pr_info("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 { + struct kvmi_event common; + struct kvmi_event_xsetbv xsetbv; + } ev; + + entry = kvm_get_supported_cpuid_entry(1); + if (!(entry->ecx & X86_FEATURE_XSAVE)) { + print_skip("XSAVE not supported, ecx 0x%x", entry->ecx); + return; + } + + enable_vcpu_event(vm, event_id); + vcpu_thread = start_vcpu_worker(&data); + + receive_event(&hdr, &ev.common, sizeof(ev), event_id); + + pr_debug("XSETBV event, XCR%u, old 0x%llx, new 0x%llx\n", + ev.xsetbv.xcr, ev.xsetbv.old_value, ev.xsetbv.new_value); + + reply_to_event(&hdr, &ev.common, 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)); @@ -1457,6 +1540,7 @@ 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 d4b39d0800ee..761d3fccddce 100644 --- a/virt/kvm/introspection/kvmi.c +++ b/virt/kvm/introspection/kvmi.c @@ -102,6 +102,7 @@ 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);