[RFC,v6,52/92] kvm: introspection: add KVMI_GET_CPUID
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Message ID 20190809160047.8319-53-alazar@bitdefender.com
State New
Headers show
Series
  • VM introspection
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Commit Message

Adalbert Lazăr Aug. 9, 2019, 4 p.m. UTC
From: Marian Rotariu <marian.c.rotariu@gmail.com>

This command returns a CPUID leaf (as seen by the guest OS).

Signed-off-by: Marian Rotariu <marian.c.rotariu@gmail.com>
Signed-off-by: Adalbert Lazăr <alazar@bitdefender.com>
---
 Documentation/virtual/kvm/kvmi.rst | 36 ++++++++++++++++++++++++++++++
 arch/x86/include/uapi/asm/kvmi.h   | 12 ++++++++++
 arch/x86/kvm/kvmi.c                | 19 ++++++++++++++++
 include/uapi/linux/kvm_para.h      |  1 +
 virt/kvm/kvmi_int.h                |  3 +++
 virt/kvm/kvmi_msg.c                | 16 +++++++++++++
 6 files changed, 87 insertions(+)

Patch
diff mbox series

diff --git a/Documentation/virtual/kvm/kvmi.rst b/Documentation/virtual/kvm/kvmi.rst
index b6722d071ab7..9e15132ed976 100644
--- a/Documentation/virtual/kvm/kvmi.rst
+++ b/Documentation/virtual/kvm/kvmi.rst
@@ -933,6 +933,42 @@  currently being handled is replied to.
 * -KVM_EINVAL - padding is not zero
 * -KVM_EAGAIN - the selected vCPU can't be introspected yet
 
+19. KVMI_GET_CPUID
+------------------
+
+:Architectures: x86
+:Versions: >= 1
+:Parameters:
+
+::
+
+	struct kvmi_vcpu_hdr;
+	struct kvmi_get_cpuid {
+		__u32 function;
+		__u32 index;
+	};
+
+:Returns:
+
+::
+
+	struct kvmi_error_code;
+	struct kvmi_get_cpuid_reply {
+		__u32 eax;
+		__u32 ebx;
+		__u32 ecx;
+		__u32 edx;
+	};
+
+Returns a CPUID leaf (as seen by the guest OS).
+
+:Errors:
+
+* -KVM_EINVAL - the selected vCPU is invalid
+* -KVM_EINVAL - padding is not zero
+* -KVM_EAGAIN - the selected vCPU can't be introspected yet
+* -KVM_ENOENT - the selected leaf is not present or is invalid
+
 Events
 ======
 
diff --git a/arch/x86/include/uapi/asm/kvmi.h b/arch/x86/include/uapi/asm/kvmi.h
index 98fb27e1273c..fa2719226198 100644
--- a/arch/x86/include/uapi/asm/kvmi.h
+++ b/arch/x86/include/uapi/asm/kvmi.h
@@ -41,4 +41,16 @@  struct kvmi_get_registers_reply {
 	struct kvm_msrs msrs;
 };
 
+struct kvmi_get_cpuid {
+	__u32 function;
+	__u32 index;
+};
+
+struct kvmi_get_cpuid_reply {
+	__u32 eax;
+	__u32 ebx;
+	__u32 ecx;
+	__u32 edx;
+};
+
 #endif /* _UAPI_ASM_X86_KVMI_H */
diff --git a/arch/x86/kvm/kvmi.c b/arch/x86/kvm/kvmi.c
index a78771b21d2f..4615bbe9c0db 100644
--- a/arch/x86/kvm/kvmi.c
+++ b/arch/x86/kvm/kvmi.c
@@ -5,6 +5,7 @@ 
  * Copyright (C) 2019 Bitdefender S.R.L.
  */
 #include "x86.h"
+#include "cpuid.h"
 #include "../../../virt/kvm/kvmi_int.h"
 
 static void *alloc_get_registers_reply(const struct kvmi_msg_hdr *msg,
@@ -211,6 +212,24 @@  bool kvmi_arch_pf_event(struct kvm_vcpu *vcpu, gpa_t gpa, gva_t gva,
 	return ret;
 }
 
+int kvmi_arch_cmd_get_cpuid(struct kvm_vcpu *vcpu,
+			    const struct kvmi_get_cpuid *req,
+			    struct kvmi_get_cpuid_reply *rpl)
+{
+	struct kvm_cpuid_entry2 *e;
+
+	e = kvm_find_cpuid_entry(vcpu, req->function, req->index);
+	if (!e)
+		return -KVM_ENOENT;
+
+	rpl->eax = e->eax;
+	rpl->ebx = e->ebx;
+	rpl->ecx = e->ecx;
+	rpl->edx = e->edx;
+
+	return 0;
+}
+
 int kvmi_arch_cmd_get_vcpu_info(struct kvm_vcpu *vcpu,
 				struct kvmi_get_vcpu_info_reply *rpl)
 {
diff --git a/include/uapi/linux/kvm_para.h b/include/uapi/linux/kvm_para.h
index 07e3f2662b36..553f168331a4 100644
--- a/include/uapi/linux/kvm_para.h
+++ b/include/uapi/linux/kvm_para.h
@@ -19,6 +19,7 @@ 
 #define KVM_EOPNOTSUPP		95
 #define KVM_EAGAIN		11
 #define KVM_EBUSY		EBUSY
+#define KVM_ENOENT		ENOENT
 #define KVM_ENOMEM		ENOMEM
 
 #define KVM_HC_VAPIC_POLL_IRQ		1
diff --git a/virt/kvm/kvmi_int.h b/virt/kvm/kvmi_int.h
index 7bc3dd1f2298..22508d147495 100644
--- a/virt/kvm/kvmi_int.h
+++ b/virt/kvm/kvmi_int.h
@@ -230,6 +230,9 @@  int kvmi_arch_cmd_set_page_write_bitmap(struct kvmi *ikvm,
 void kvmi_arch_setup_event(struct kvm_vcpu *vcpu, struct kvmi_event *ev);
 bool kvmi_arch_pf_event(struct kvm_vcpu *vcpu, gpa_t gpa, gva_t gva,
 			u8 access);
+int kvmi_arch_cmd_get_cpuid(struct kvm_vcpu *vcpu,
+			    const struct kvmi_get_cpuid *req,
+			    struct kvmi_get_cpuid_reply *rpl);
 int kvmi_arch_cmd_get_vcpu_info(struct kvm_vcpu *vcpu,
 				struct kvmi_get_vcpu_info_reply *rpl);
 
diff --git a/virt/kvm/kvmi_msg.c b/virt/kvm/kvmi_msg.c
index 355cec70a28d..9548042de618 100644
--- a/virt/kvm/kvmi_msg.c
+++ b/virt/kvm/kvmi_msg.c
@@ -29,6 +29,7 @@  static const char *const msg_IDs[] = {
 	[KVMI_CONTROL_VM_EVENTS]     = "KVMI_CONTROL_VM_EVENTS",
 	[KVMI_EVENT]                 = "KVMI_EVENT",
 	[KVMI_EVENT_REPLY]           = "KVMI_EVENT_REPLY",
+	[KVMI_GET_CPUID]             = "KVMI_GET_CPUID",
 	[KVMI_GET_GUEST_INFO]        = "KVMI_GET_GUEST_INFO",
 	[KVMI_GET_PAGE_ACCESS]       = "KVMI_GET_PAGE_ACCESS",
 	[KVMI_GET_PAGE_WRITE_BITMAP] = "KVMI_GET_PAGE_WRITE_BITMAP",
@@ -641,6 +642,20 @@  static int handle_control_events(struct kvm_vcpu *vcpu,
 	return reply_cb(vcpu, msg, ec, NULL, 0);
 }
 
+static int handle_get_cpuid(struct kvm_vcpu *vcpu,
+			    const struct kvmi_msg_hdr *msg,
+			    const void *req, vcpu_reply_fct reply_cb)
+{
+	struct kvmi_get_cpuid_reply rpl;
+	int ec;
+
+	memset(&rpl, 0, sizeof(rpl));
+
+	ec = kvmi_arch_cmd_get_cpuid(vcpu, req, &rpl);
+
+	return reply_cb(vcpu, msg, ec, &rpl, sizeof(rpl));
+}
+
 /*
  * These commands are executed on the vCPU thread. The receiving thread
  * passes the messages using a newly allocated 'struct kvmi_vcpu_cmd'
@@ -652,6 +667,7 @@  static int(*const msg_vcpu[])(struct kvm_vcpu *,
 			      vcpu_reply_fct) = {
 	[KVMI_CONTROL_EVENTS]   = handle_control_events,
 	[KVMI_EVENT_REPLY]      = handle_event_reply,
+	[KVMI_GET_CPUID]        = handle_get_cpuid,
 	[KVMI_GET_REGISTERS]    = handle_get_registers,
 	[KVMI_GET_VCPU_INFO]    = handle_get_vcpu_info,
 	[KVMI_SET_REGISTERS]    = handle_set_registers,