This can be used by the introspection tool to emulate SSE instructions.
Signed-off-by: Adalbert Lazăr <alazar@xxxxxxxxxxxxxxx>
---
Documentation/virt/kvm/kvmi.rst | 33 +++++++++++++++++++
arch/x86/include/uapi/asm/kvmi.h | 9 +++++
arch/x86/kvm/kvmi_msg.c | 21 ++++++++++++
include/uapi/linux/kvmi.h | 1 +
.../testing/selftests/kvm/x86_64/kvmi_test.c | 33 +++++++++++++++++++
5 files changed, 97 insertions(+)
diff --git a/Documentation/virt/kvm/kvmi.rst b/Documentation/virt/kvm/kvmi.rst
index d3a0bea64e02..389d69e3fd7e 100644
--- a/Documentation/virt/kvm/kvmi.rst
+++ b/Documentation/virt/kvm/kvmi.rst
@@ -778,6 +778,39 @@ exception.
* -KVM_EBUSY - another *KVMI_VCPU_INJECT_EXCEPTION*-*KVMI_VCPU_EVENT_TRAP*
pair is in progress
+17. KVMI_VCPU_GET_XCR
+---------------------
+
+:Architectures: x86
+:Versions: >= 1
+:Parameters:
+
+::
+
+ struct kvmi_vcpu_hdr;
+ struct kvmi_vcpu_get_xcr {
+ __u8 xcr;
+ __u8 padding[7];
+ };
+
+:Returns:
+
+::
+
+ struct kvmi_error_code;
+ struct kvmi_vcpu_get_xcr_reply {
+ __u64 value;
+ };
+
+Returns the value of an extended control register XCR.
+
+:Errors:
+
+* -KVM_EINVAL - the selected vCPU is invalid
+* -KVM_EINVAL - the specified control register is not XCR0
+* -KVM_EINVAL - the padding is not zero
+* -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 604a8b3d4ac2..c0a73051d667 100644
--- a/arch/x86/include/uapi/asm/kvmi.h
+++ b/arch/x86/include/uapi/asm/kvmi.h
@@ -102,4 +102,13 @@ struct kvmi_vcpu_event_xsetbv {
__u64 new_value;
};
+struct kvmi_vcpu_get_xcr {
+ __u8 xcr;
+ __u8 padding[7];
+};
+
+struct kvmi_vcpu_get_xcr_reply {
+ __u64 value;
+};
+
#endif /* _UAPI_ASM_X86_KVMI_H */
diff --git a/arch/x86/kvm/kvmi_msg.c b/arch/x86/kvm/kvmi_msg.c
index c767b969df53..21624568e329 100644
--- a/arch/x86/kvm/kvmi_msg.c
+++ b/arch/x86/kvm/kvmi_msg.c
@@ -174,11 +174,32 @@ static int handle_vcpu_inject_exception(const struct kvmi_vcpu_msg_job *job,
return kvmi_msg_vcpu_reply(job, msg, ec, NULL, 0);
}
+static int handle_vcpu_get_xcr(const struct kvmi_vcpu_msg_job *job,
+ const struct kvmi_msg_hdr *msg,
+ const void *_req)
+{
+ const struct kvmi_vcpu_get_xcr *req = _req;
+ struct kvmi_vcpu_get_xcr_reply rpl;
+ int ec = 0;
+
+ memset(&rpl, 0, sizeof(rpl));
+
+ if (non_zero_padding(req->padding, ARRAY_SIZE(req->padding)))
+ ec = -KVM_EINVAL;
+ else if (req->xcr != 0)
+ ec = -KVM_EINVAL;
+ else
+ rpl.value = job->vcpu->arch.xcr0;
+
+ return kvmi_msg_vcpu_reply(job, msg, ec, &rpl, sizeof(rpl));
+}
+
static const kvmi_vcpu_msg_job_fct msg_vcpu[] = {
[KVMI_VCPU_CONTROL_CR] = handle_vcpu_control_cr,
[KVMI_VCPU_GET_CPUID] = handle_vcpu_get_cpuid,
[KVMI_VCPU_GET_INFO] = handle_vcpu_get_info,
[KVMI_VCPU_GET_REGISTERS] = handle_vcpu_get_registers,
+ [KVMI_VCPU_GET_XCR] = handle_vcpu_get_xcr,
[KVMI_VCPU_INJECT_EXCEPTION] = handle_vcpu_inject_exception,
[KVMI_VCPU_SET_REGISTERS] = handle_vcpu_set_registers,
};
diff --git a/include/uapi/linux/kvmi.h b/include/uapi/linux/kvmi.h
index 4b71c6b0b16c..ac23754627ff 100644
--- a/include/uapi/linux/kvmi.h
+++ b/include/uapi/linux/kvmi.h
@@ -43,6 +43,7 @@ enum {
KVMI_VCPU_GET_CPUID = KVMI_VCPU_MESSAGE_ID(5),
KVMI_VCPU_CONTROL_CR = KVMI_VCPU_MESSAGE_ID(6),
KVMI_VCPU_INJECT_EXCEPTION = KVMI_VCPU_MESSAGE_ID(7),
+ KVMI_VCPU_GET_XCR = KVMI_VCPU_MESSAGE_ID(8),
KVMI_NEXT_VCPU_MESSAGE
};
diff --git a/tools/testing/selftests/kvm/x86_64/kvmi_test.c b/tools/testing/selftests/kvm/x86_64/kvmi_test.c
index 380aa3d2d8f3..d9497727e859 100644
--- a/tools/testing/selftests/kvm/x86_64/kvmi_test.c
+++ b/tools/testing/selftests/kvm/x86_64/kvmi_test.c
@@ -1405,6 +1405,38 @@ static void test_event_xsetbv(struct kvm_vm *vm)
disable_vcpu_event(vm, event_id);
}
+static void cmd_vcpu_get_xcr(struct kvm_vm *vm, u8 xcr, u64 *value,
+ int expected_err)
+{
+ struct {
+ struct kvmi_msg_hdr hdr;
+ struct kvmi_vcpu_hdr vcpu_hdr;
+ struct kvmi_vcpu_get_xcr cmd;
+ } req = { 0 };
+ struct kvmi_vcpu_get_xcr_reply rpl = { 0 };
+ int r;
+
+ req.cmd.xcr = xcr;
+
+ r = do_vcpu0_command(vm, KVMI_VCPU_GET_XCR, &req.hdr, sizeof(req),
+ &rpl, sizeof(rpl));
+ TEST_ASSERT(r == expected_err,
+ "KVMI_VCPU_GET_XCR failed, error %d (%s), expected %d\n",
+ -r, kvm_strerror(-r), expected_err);
+
+ *value = r == 0 ? rpl.value : 0;
+}
+
+static void test_cmd_vcpu_get_xcr(struct kvm_vm *vm)
+{
+ u8 xcr0 = 0, xcr1 = 1;
+ u64 value;
+
+ cmd_vcpu_get_xcr(vm, xcr0, &value, 0);
+ pr_debug("XCR0 0x%lx\n", value);
+ cmd_vcpu_get_xcr(vm, xcr1, &value, -KVM_EINVAL);
+}
+
static void test_introspection(struct kvm_vm *vm)
{
srandom(time(0));
@@ -1431,6 +1463,7 @@ static void test_introspection(struct kvm_vm *vm)
test_cmd_vcpu_control_cr(vm);
test_cmd_vcpu_inject_exception(vm);
test_event_xsetbv(vm);
+ test_cmd_vcpu_get_xcr(vm);
unhook_introspection(vm);
}
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