[PATCH v6 2/7] KVM: x86: Add infrastructure for MSR filtering

From: Alexander Graf
Date: Wed Sep 02 2020 - 09:00:31 EST


In the following commits we will add pieces of MSR filtering.
To ensure that code compiles even with the feature half-merged, let's add
a few stubs and struct definitions before the real patches start.

Signed-off-by: Alexander Graf <graf@xxxxxxxxxx>
---
arch/x86/include/asm/kvm_host.h | 1 +
arch/x86/include/uapi/asm/kvm.h | 2 ++
arch/x86/kvm/x86.c | 6 ++++++
arch/x86/kvm/x86.h | 1 +
4 files changed, 10 insertions(+)

diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index 6608c8efbfa1..a9e3cc13bca6 100644
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -1272,6 +1272,7 @@ struct kvm_x86_ops {
int (*enable_direct_tlbflush)(struct kvm_vcpu *vcpu);

void (*migrate_timers)(struct kvm_vcpu *vcpu);
+ void (*msr_filter_changed)(struct kvm_vcpu *vcpu);
};

struct kvm_x86_nested_ops {
diff --git a/arch/x86/include/uapi/asm/kvm.h b/arch/x86/include/uapi/asm/kvm.h
index 0780f97c1850..50650cfd235a 100644
--- a/arch/x86/include/uapi/asm/kvm.h
+++ b/arch/x86/include/uapi/asm/kvm.h
@@ -192,6 +192,8 @@ struct kvm_msr_list {
__u32 indices[0];
};

+#define KVM_MSR_ALLOW_READ (1 << 0)
+#define KVM_MSR_ALLOW_WRITE (1 << 1)

struct kvm_cpuid_entry {
__u32 function;
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 4d285bf054fb..6024d1cdea5a 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -1472,6 +1472,12 @@ void kvm_enable_efer_bits(u64 mask)
}
EXPORT_SYMBOL_GPL(kvm_enable_efer_bits);

+bool kvm_msr_allowed(struct kvm_vcpu *vcpu, u32 index, u32 type)
+{
+ return true;
+}
+EXPORT_SYMBOL_GPL(kvm_msr_allowed);
+
/*
* Write @data into the MSR specified by @index. Select MSR specific fault
* checks are bypassed if @host_initiated is %true.
diff --git a/arch/x86/kvm/x86.h b/arch/x86/kvm/x86.h
index 6eb62e97e59f..1d67d9168b8c 100644
--- a/arch/x86/kvm/x86.h
+++ b/arch/x86/kvm/x86.h
@@ -365,5 +365,6 @@ void kvm_load_guest_xsave_state(struct kvm_vcpu *vcpu);
void kvm_load_host_xsave_state(struct kvm_vcpu *vcpu);
u64 kvm_spec_ctrl_valid_bits(struct kvm_vcpu *vcpu);
bool kvm_vcpu_exit_request(struct kvm_vcpu *vcpu);
+bool kvm_msr_allowed(struct kvm_vcpu *vcpu, u32 index, u32 type);

#endif
--
2.17.1




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