[PATCH v2 3/5] KVM: implement new perf interfaces

[Tianyi Liu <i.pear@outlook.com>]

This patch provides two KVM implementations for the following new perf
interfaces, just redirecting them to the arch-specific implementations:

- get_frame_pointer: Return the frame pointer of the running vm.
- read_virt: Read data from a virtual address of the running vm.

Signed-off-by: Tianyi Liu <i.pear@outlook.com>
---
 virt/kvm/kvm_main.c | 25 +++++++++++++++++++++++++
 1 file changed, 25 insertions(+)

diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
index 486800a70..6fd6ee6c0 100644
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -6018,6 +6018,9 @@ static unsigned int kvm_guest_state(void)
 	if (!kvm_arch_vcpu_in_kernel(vcpu))
 		state |= PERF_GUEST_USER;
 
+	if (kvm_arch_vcpu_is_64bit(vcpu))
+		state |= PERF_GUEST_64BIT;
+
 	return state;
 }
 
@@ -6032,9 +6035,31 @@ static unsigned long kvm_guest_get_ip(void)
 	return kvm_arch_vcpu_get_ip(vcpu);
 }
 
+static unsigned long kvm_guest_get_frame_pointer(void)
+{
+	struct kvm_vcpu *vcpu = kvm_get_running_vcpu();
+
+	if (WARN_ON_ONCE(!kvm_arch_pmi_in_guest(vcpu)))
+		return 0;
+
+	return kvm_arch_vcpu_get_frame_pointer(vcpu);
+}
+
+static bool kvm_guest_read_virt(void *addr, void *dest, unsigned int length)
+{
+	struct kvm_vcpu *vcpu = kvm_get_running_vcpu();
+
+	if (WARN_ON_ONCE(!kvm_arch_pmi_in_guest(vcpu)))
+		return false;
+
+	return kvm_arch_vcpu_read_virt(vcpu, addr, dest, length);
+}
+
 static struct perf_guest_info_callbacks kvm_guest_cbs = {
 	.state			= kvm_guest_state,
 	.get_ip			= kvm_guest_get_ip,
+	.get_frame_pointer	= kvm_guest_get_frame_pointer,
+	.read_virt		= kvm_guest_read_virt,
 	.handle_intel_pt_intr	= NULL,
 };
 
-- 
2.42.0