From: Ștefan Șicleru <ssicl...@bitdefender.com>
The introspection tool uses this function to check the hardware support
for EPT switching, which can be used either to singlestep vCPUs
on a unprotected EPT view or to use #VE in order to avoid filter out
VM-exits caused by EPT violations.
Signed-off-by: Ștefan Șicleru <ssicl...@bitdefender.com>
Signed-off-by: Adalbert Lazăr <ala...@bitdefender.com>
---
Documentation/virt/kvm/kvmi.rst | 34 +++++++++++++++++++
arch/x86/include/uapi/asm/kvmi.h | 6 ++++
arch/x86/kvm/kvmi.c | 5 +++
include/uapi/linux/kvmi.h | 1 +
.../testing/selftests/kvm/x86_64/kvmi_test.c | 28 +++++++++++++++
virt/kvm/introspection/kvmi_int.h | 1 +
virt/kvm/introspection/kvmi_msg.c | 14 ++++++++
7 files changed, 89 insertions(+)
diff --git a/Documentation/virt/kvm/kvmi.rst b/Documentation/virt/kvm/kvmi.rst
index 234eacec4db1..76a2d0125f78 100644
--- a/Documentation/virt/kvm/kvmi.rst
+++ b/Documentation/virt/kvm/kvmi.rst
@@ -1120,6 +1120,40 @@ the address cannot be translated.
* -KVM_EINVAL - the padding is not zero
* -KVM_EAGAIN - the selected vCPU can't be introspected yet
+26. KVMI_VCPU_GET_EPT_VIEW
+--------------------------
+
+:Architecture: x86
+:Versions: >= 1
+:Parameters:
+
+::
+
+ struct kvmi_vcpu_hdr;
+
+:Returns:
+
+::
+
+ struct kvmi_error_code;
+ struct kvmi_vcpu_get_ept_view_reply {
+ __u16 view;
+ __u16 padding1;
+ __u32 padding2;
+ };
+
+Returns the EPT ``view`` the provided vCPU operates on.
+
+Before getting EPT views, the introspection tool should use
+*KVMI_GET_VERSION* to check if the hardware has support for VMFUNC and
+EPTP switching mechanism (see **KVMI_GET_VERSION**). If the hardware
+does not provide support for these features, the returned EPT view will
+be zero.
+
+* -KVM_EINVAL - the selected vCPU is invalid
+* -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 51b399d50a2a..3087c685c232 100644
--- a/arch/x86/include/uapi/asm/kvmi.h
+++ b/arch/x86/include/uapi/asm/kvmi.h
@@ -152,4 +152,10 @@ struct kvmi_features {
__u8 padding[5];
};
+struct kvmi_vcpu_get_ept_view_reply {
+ __u16 view;
+ __u16 padding1;
+ __u32 padding2;
+};
+
#endif /* _UAPI_ASM_X86_KVMI_H */
diff --git a/arch/x86/kvm/kvmi.c b/arch/x86/kvm/kvmi.c
index 25c1f8f2e221..bd31809ff812 100644
--- a/arch/x86/kvm/kvmi.c
+++ b/arch/x86/kvm/kvmi.c
@@ -1417,3 +1417,8 @@ bool kvmi_update_ad_flags(struct kvm_vcpu *vcpu)
return ret;
}
+
+u16 kvmi_arch_cmd_get_ept_view(struct kvm_vcpu *vcpu)
+{
+ return kvm_get_ept_view(vcpu);
+}
diff --git a/include/uapi/linux/kvmi.h b/include/uapi/linux/kvmi.h
index 3c15c17d28e3..cf3422ec60a8 100644
--- a/include/uapi/linux/kvmi.h
+++ b/include/uapi/linux/kvmi.h
@@ -49,6 +49,7 @@ enum {
KVMI_VCPU_CONTROL_SINGLESTEP = 24,
KVMI_VCPU_TRANSLATE_GVA = 25,
+ KVMI_VCPU_GET_EPT_VIEW = 26,
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 33fffcb3a171..74eafbcae14a 100644
--- a/tools/testing/selftests/kvm/x86_64/kvmi_test.c
+++ b/tools/testing/selftests/kvm/x86_64/kvmi_test.c
@@ -2071,6 +2071,33 @@ static void test_cmd_translate_gva(struct kvm_vm *vm)
(vm_vaddr_t)-1, (vm_paddr_t)-1);
}
+static __u16 get_ept_view(struct kvm_vm *vm)
+{
+ struct {
+ struct kvmi_msg_hdr hdr;
+ struct kvmi_vcpu_hdr vcpu_hdr;
+ } req = {};
+ struct kvmi_vcpu_get_ept_view_reply rpl;
+
+ test_vcpu0_command(vm, KVMI_VCPU_GET_EPT_VIEW,
+ &req.hdr, sizeof(req), &rpl, sizeof(rpl));
+
+ return rpl.view;
+}
+
+static void test_cmd_vcpu_get_ept_view(struct kvm_vm *vm)
+{
+ __u16 view;
+
+ if (!features.eptp) {
+ print_skip("EPT views not supported");
+ return;
+ }
+
+ view = get_ept_view(vm);
+ pr_info("EPT view %u\n", view);
+}
+
static void test_introspection(struct kvm_vm *vm)
{
srandom(time(0));
@@ -2107,6 +2134,7 @@ static void test_introspection(struct kvm_vm *vm)
test_event_pf(vm);
test_cmd_vcpu_control_singlestep(vm);
test_cmd_translate_gva(vm);
+ test_cmd_vcpu_get_ept_view(vm);
unhook_introspection(vm);
}
diff --git a/virt/kvm/introspection/kvmi_int.h
b/virt/kvm/introspection/kvmi_int.h
index cb8453f0fb87..f88999bf59e8 100644
--- a/virt/kvm/introspection/kvmi_int.h
+++ b/virt/kvm/introspection/kvmi_int.h
@@ -142,5 +142,6 @@ void kvmi_arch_features(struct kvmi_features *feat);
bool kvmi_arch_start_singlestep(struct kvm_vcpu *vcpu);
bool kvmi_arch_stop_singlestep(struct kvm_vcpu *vcpu);
gpa_t kvmi_arch_cmd_translate_gva(struct kvm_vcpu *vcpu, gva_t gva);
+u16 kvmi_arch_cmd_get_ept_view(struct kvm_vcpu *vcpu);
#endif
diff --git a/virt/kvm/introspection/kvmi_msg.c
b/virt/kvm/introspection/kvmi_msg.c
index d8874bd7a8b7..6cb3473190db 100644
--- a/virt/kvm/introspection/kvmi_msg.c
+++ b/virt/kvm/introspection/kvmi_msg.c
@@ -661,6 +661,19 @@ static int handle_vcpu_translate_gva(const struct
kvmi_vcpu_msg_job *job,
return kvmi_msg_vcpu_reply(job, msg, 0, &rpl, sizeof(rpl));
}
+static int handle_vcpu_get_ept_view(const struct kvmi_vcpu_msg_job *job,
+ const struct kvmi_msg_hdr *msg,
+ const void *req)
+{
+ struct kvmi_vcpu_get_ept_view_reply rpl;
+
+ memset(&rpl, 0, sizeof(rpl));
+
+ rpl.view = kvmi_arch_cmd_get_ept_view(job->vcpu);
+
+ return kvmi_msg_vcpu_reply(job, msg, 0, &rpl, sizeof(rpl));
+}
+
/*
* These functions are executed from the vCPU thread. The receiving thread
* passes the messages using a newly allocated 'struct kvmi_vcpu_msg_job'
@@ -675,6 +688,7 @@ static int(*const msg_vcpu[])(const struct
kvmi_vcpu_msg_job *,
[KVMI_VCPU_CONTROL_MSR] = handle_vcpu_control_msr,
[KVMI_VCPU_CONTROL_SINGLESTEP] = handle_vcpu_control_singlestep,
[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,
[KVMI_VCPU_GET_MTRR_TYPE] = handle_vcpu_get_mtrr_type,
[KVMI_VCPU_GET_REGISTERS] = handle_vcpu_get_registers,
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