From mboxrd@z Thu Jan 1 00:00:00 1970 From: =?UTF-8?q?Adalbert=20Laz=C4=83r?= Subject: [RFC PATCH v1 32/34] KVM: introspection: add KVMI_VCPU_SET_VE_INFO/KVMI_VCPU_DISABLE_VE Date: Wed, 22 Jul 2020 19:01:19 +0300 Message-ID: <20200722160121.9601-33-alazar@bitdefender.com> References: <20200722160121.9601-1-alazar@bitdefender.com> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Return-path: In-Reply-To: <20200722160121.9601-1-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?=C8=98tefan=20=C8=98icleru?= , =?UTF-8?q?Adalbert=20Laz=C4=83r?= List-Id: virtualization@lists.linuxfoundation.org From: Ștefan Șicleru The introspection tool can use #VE to reduce the number of VM-exits caused by SPT violations for some guests. Signed-off-by: Ștefan Șicleru Signed-off-by: Adalbert Lazăr --- Documentation/virt/kvm/kvmi.rst | 63 +++++++++++++++++++ arch/x86/include/uapi/asm/kvmi.h | 8 +++ arch/x86/kvm/kvmi.c | 19 ++++++ include/uapi/linux/kvmi.h | 2 + .../testing/selftests/kvm/x86_64/kvmi_test.c | 52 +++++++++++++++ virt/kvm/introspection/kvmi_int.h | 3 + virt/kvm/introspection/kvmi_msg.c | 30 +++++++++ 7 files changed, 177 insertions(+) diff --git a/Documentation/virt/kvm/kvmi.rst b/Documentation/virt/kvm/kvmi.rst index caa51fccc463..c50c40638d46 100644 --- a/Documentation/virt/kvm/kvmi.rst +++ b/Documentation/virt/kvm/kvmi.rst @@ -1230,6 +1230,69 @@ is terminated. * -KVM_EINVAL - padding is not zero * -KVM_EINVAL - the selected EPT view is not valid +29. KVMI_VCPU_SET_VE_INFO +------------------------- + +:Architecture: x86 +:Versions: >= 1 +:Parameters: + +:: + + struct kvmi_vcpu_hdr; + struct kvmi_vcpu_set_ve_info { + __u64 gpa; + __u8 trigger_vmexit; + __u8 padding1; + __u16 padding2; + __u32 padding3; + }; + +:Returns: + +:: + + struct kvmi_error_code; + +Configures the guest physical address for the #VE info page and enables +the #VE mechanism. If ``trigger_vmexit`` is true, any virtualization +exception will trigger a vm-exit. Otherwise, the exception is delivered +using gate descriptor 20 from the Interrupt Descriptor Table (IDT). + +:Errors: + +* -KVM_EINVAL - the selected vCPU is invalid +* -KVM_EINVAL - one of the specified GPAs is invalid +* -KVM_EOPNOTSUPP - the hardware does not support #VE +* -KVM_EINVAL - padding is not zero +* -KVM_EAGAIN - the selected vCPU can't be introspected yet + +30. KVMI_VCPU_DISABLE_VE +------------------------ + +:Architecture: x86 +:Versions: >= 1 +:Parameters: + +:: + + struct kvmi_vcpu_hdr; + +:Returns: + +:: + + struct kvmi_error_code; + +Disables the #VE mechanism. All EPT violations will trigger a vm-exit, +regardless of the corresponding spte 63rd bit (SVE) for the GPA that +triggered the EPT violation within a specific EPT view. + +:Errors: + +* -KVM_EINVAL - the selected vCPU is invalid +* -KVM_EAGAIN - the selected vCPU can't be introspected yet + Events ====== diff --git a/arch/x86/include/uapi/asm/kvmi.h b/arch/x86/include/uapi/asm/kvmi.h index 56992dacfb69..d925e6d49f50 100644 --- a/arch/x86/include/uapi/asm/kvmi.h +++ b/arch/x86/include/uapi/asm/kvmi.h @@ -174,4 +174,12 @@ struct kvmi_vcpu_control_ept_view { __u32 padding2; }; +struct kvmi_vcpu_set_ve_info { + __u64 gpa; + __u8 trigger_vmexit; + __u8 padding1; + __u16 padding2; + __u32 padding3; +}; + #endif /* _UAPI_ASM_X86_KVMI_H */ diff --git a/arch/x86/kvm/kvmi.c b/arch/x86/kvm/kvmi.c index 3e8c83623703..e101ac390809 100644 --- a/arch/x86/kvm/kvmi.c +++ b/arch/x86/kvm/kvmi.c @@ -1464,3 +1464,22 @@ int kvmi_arch_cmd_control_ept_view(struct kvm_vcpu *vcpu, u16 view, return kvm_x86_ops.control_ept_view(vcpu, view, visible); } + +int kvmi_arch_cmd_set_ve_info(struct kvm_vcpu *vcpu, u64 gpa, + bool trigger_vmexit) +{ + unsigned long ve_info = (unsigned long) gpa; + + if (!kvm_x86_ops.set_ve_info) + return -KVM_EINVAL; + + return kvm_x86_ops.set_ve_info(vcpu, ve_info, trigger_vmexit); +} + +int kvmi_arch_cmd_disable_ve(struct kvm_vcpu *vcpu) +{ + if (!kvm_x86_ops.disable_ve) + return 0; + + return kvm_x86_ops.disable_ve(vcpu); +} diff --git a/include/uapi/linux/kvmi.h b/include/uapi/linux/kvmi.h index 505a865cd115..a17cd1fa16d0 100644 --- a/include/uapi/linux/kvmi.h +++ b/include/uapi/linux/kvmi.h @@ -52,6 +52,8 @@ enum { KVMI_VCPU_GET_EPT_VIEW = 26, KVMI_VCPU_SET_EPT_VIEW = 27, KVMI_VCPU_CONTROL_EPT_VIEW = 28, + KVMI_VCPU_SET_VE_INFO = 29, + KVMI_VCPU_DISABLE_VE = 30, KVMI_NUM_MESSAGES }; diff --git a/tools/testing/selftests/kvm/x86_64/kvmi_test.c b/tools/testing/selftests/kvm/x86_64/kvmi_test.c index 4e099cbfcf4e..a3ea22f546ec 100644 --- a/tools/testing/selftests/kvm/x86_64/kvmi_test.c +++ b/tools/testing/selftests/kvm/x86_64/kvmi_test.c @@ -35,6 +35,10 @@ static vm_vaddr_t test_gva; static void *test_hva; static vm_paddr_t test_gpa; +static vm_vaddr_t test_ve_info_gva; +static void *test_ve_info_hva; +static vm_paddr_t test_ve_info_gpa; + static uint8_t test_write_pattern; static int page_size; @@ -2258,6 +2262,43 @@ static void test_cmd_vcpu_vmfunc(struct kvm_vm *vm) test_guest_switch_to_visible_view(vm); } +static void enable_ve(struct kvm_vm *vm) +{ + struct { + struct kvmi_msg_hdr hdr; + struct kvmi_vcpu_hdr vcpu_hdr; + struct kvmi_vcpu_set_ve_info cmd; + } req = {}; + + req.cmd.gpa = test_ve_info_gpa; + req.cmd.trigger_vmexit = 1; + + test_vcpu0_command(vm, KVMI_VCPU_SET_VE_INFO, &req.hdr, + sizeof(req), NULL, 0); +} + +static void disable_ve(struct kvm_vm *vm) +{ + struct { + struct kvmi_msg_hdr hdr; + struct kvmi_vcpu_hdr vcpu_hdr; + } req = {}; + + test_vcpu0_command(vm, KVMI_VCPU_DISABLE_VE, &req.hdr, + sizeof(req), NULL, 0); +} + +static void test_virtualization_exceptions(struct kvm_vm *vm) +{ + if (!features.ve) { + print_skip("#VE not supported"); + return; + } + + enable_ve(vm); + disable_ve(vm); +} + static void test_introspection(struct kvm_vm *vm) { srandom(time(0)); @@ -2297,6 +2338,7 @@ static void test_introspection(struct kvm_vm *vm) test_cmd_vcpu_get_ept_view(vm); test_cmd_vcpu_set_ept_view(vm); test_cmd_vcpu_vmfunc(vm); + test_virtualization_exceptions(vm); unhook_introspection(vm); } @@ -2311,6 +2353,16 @@ static void setup_test_pages(struct kvm_vm *vm) memset(test_hva, 0, page_size); test_gpa = addr_gva2gpa(vm, test_gva); + + /* Allocate #VE info page */ + test_ve_info_gva = vm_vaddr_alloc(vm, page_size, KVM_UTIL_MIN_VADDR, + 0, 0); + sync_global_to_guest(vm, test_ve_info_gva); + + test_ve_info_hva = addr_gva2hva(vm, test_ve_info_gva); + memset(test_ve_info_hva, 0, page_size); + + test_ve_info_gpa = addr_gva2gpa(vm, test_ve_info_gva); } int main(int argc, char *argv[]) diff --git a/virt/kvm/introspection/kvmi_int.h b/virt/kvm/introspection/kvmi_int.h index fc6dbd3a6472..a0062fbde49e 100644 --- a/virt/kvm/introspection/kvmi_int.h +++ b/virt/kvm/introspection/kvmi_int.h @@ -151,5 +151,8 @@ u16 kvmi_arch_cmd_get_ept_view(struct kvm_vcpu *vcpu); int kvmi_arch_cmd_set_ept_view(struct kvm_vcpu *vcpu, u16 view); int kvmi_arch_cmd_control_ept_view(struct kvm_vcpu *vcpu, u16 view, bool visible); +int kvmi_arch_cmd_set_ve_info(struct kvm_vcpu *vcpu, u64 gpa, + bool trigger_vmexit); +int kvmi_arch_cmd_disable_ve(struct kvm_vcpu *vcpu); #endif diff --git a/virt/kvm/introspection/kvmi_msg.c b/virt/kvm/introspection/kvmi_msg.c index 696857f6d008..664b78d545c3 100644 --- a/virt/kvm/introspection/kvmi_msg.c +++ b/virt/kvm/introspection/kvmi_msg.c @@ -711,6 +711,34 @@ static int handle_vcpu_control_ept_view(const struct kvmi_vcpu_msg_job *job, return kvmi_msg_vcpu_reply(job, msg, ec, NULL, 0); } +static int handle_vcpu_set_ve_info(const struct kvmi_vcpu_msg_job *job, + const struct kvmi_msg_hdr *msg, + const void *_req) +{ + const struct kvmi_vcpu_set_ve_info *req = _req; + bool trigger_vmexit = !!req->trigger_vmexit; + int ec; + + if (req->padding1 || req->padding2 || req->padding3) + ec = -KVM_EINVAL; + else + ec = kvmi_arch_cmd_set_ve_info(job->vcpu, req->gpa, + trigger_vmexit); + + return kvmi_msg_vcpu_reply(job, msg, ec, NULL, 0); +} + +static int handle_vcpu_disable_ve(const struct kvmi_vcpu_msg_job *job, + const struct kvmi_msg_hdr *msg, + const void *req) +{ + int ec; + + ec = kvmi_arch_cmd_disable_ve(job->vcpu); + + return kvmi_msg_vcpu_reply(job, msg, ec, NULL, 0); +} + /* * These functions are executed from the vCPU thread. The receiving thread * passes the messages using a newly allocated 'struct kvmi_vcpu_msg_job' @@ -725,6 +753,7 @@ static int(*const msg_vcpu[])(const struct kvmi_vcpu_msg_job *, [KVMI_VCPU_CONTROL_EVENTS] = handle_vcpu_control_events, [KVMI_VCPU_CONTROL_MSR] = handle_vcpu_control_msr, [KVMI_VCPU_CONTROL_SINGLESTEP] = handle_vcpu_control_singlestep, + [KVMI_VCPU_DISABLE_VE] = handle_vcpu_disable_ve, [KVMI_VCPU_GET_CPUID] = handle_vcpu_get_cpuid, [KVMI_VCPU_GET_EPT_VIEW] = handle_vcpu_get_ept_view, [KVMI_VCPU_GET_INFO] = handle_vcpu_get_info, @@ -736,6 +765,7 @@ static int(*const msg_vcpu[])(const struct kvmi_vcpu_msg_job *, [KVMI_VCPU_SET_EPT_VIEW] = handle_vcpu_set_ept_view, [KVMI_VCPU_SET_REGISTERS] = handle_vcpu_set_registers, [KVMI_VCPU_SET_XSAVE] = handle_vcpu_set_xsave, + [KVMI_VCPU_SET_VE_INFO] = handle_vcpu_set_ve_info, [KVMI_VCPU_TRANSLATE_GVA] = handle_vcpu_translate_gva, };