diff options
| author | Alexander Graf <graf@amazon.com> | 2020-09-25 16:34:21 +0200 |
|---|---|---|
| committer | Paolo Bonzini <pbonzini@redhat.com> | 2020-09-28 07:58:08 -0400 |
| commit | 1a155254ff937ac92cf9940d273ea597b2c667a2 (patch) | |
| tree | de43208fede8e696571cfd3c8e21b220358ae716 /include | |
| parent | 3eb900173c71392087f4b0ada66f67ceae7e75f0 (diff) | |
KVM: x86: Introduce MSR filtering
It's not desireable to have all MSRs always handled by KVM kernel space. Some
MSRs would be useful to handle in user space to either emulate behavior (like
uCode updates) or differentiate whether they are valid based on the CPU model.
To allow user space to specify which MSRs it wants to see handled by KVM,
this patch introduces a new ioctl to push filter rules with bitmaps into
KVM. Based on these bitmaps, KVM can then decide whether to reject MSR access.
With the addition of KVM_CAP_X86_USER_SPACE_MSR it can also deflect the
denied MSR events to user space to operate on.
If no filter is populated, MSR handling stays identical to before.
Signed-off-by: Alexander Graf <graf@amazon.com>
Message-Id: <20200925143422.21718-8-graf@amazon.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Diffstat (limited to 'include')
| -rw-r--r-- | include/uapi/linux/kvm.h | 5 |
1 files changed, 5 insertions, 0 deletions
diff --git a/include/uapi/linux/kvm.h b/include/uapi/linux/kvm.h index 31292a3cdfc2..58f43aa1fc21 100644 --- a/include/uapi/linux/kvm.h +++ b/include/uapi/linux/kvm.h @@ -421,6 +421,7 @@ struct kvm_run { __u8 pad[7]; #define KVM_MSR_EXIT_REASON_INVAL (1 << 0) #define KVM_MSR_EXIT_REASON_UNKNOWN (1 << 1) +#define KVM_MSR_EXIT_REASON_FILTER (1 << 2) __u32 reason; /* kernel -> user */ __u32 index; /* kernel -> user */ __u64 data; /* kernel <-> user */ @@ -1050,6 +1051,7 @@ struct kvm_ppc_resize_hpt { #define KVM_CAP_S390_DIAG318 186 #define KVM_CAP_STEAL_TIME 187 #define KVM_CAP_X86_USER_SPACE_MSR 188 +#define KVM_CAP_X86_MSR_FILTER 189 #ifdef KVM_CAP_IRQ_ROUTING @@ -1551,6 +1553,9 @@ struct kvm_pv_cmd { /* Available with KVM_CAP_S390_PROTECTED */ #define KVM_S390_PV_COMMAND _IOWR(KVMIO, 0xc5, struct kvm_pv_cmd) +/* Available with KVM_CAP_X86_MSR_FILTER */ +#define KVM_X86_SET_MSR_FILTER _IOW(KVMIO, 0xc6, struct kvm_msr_filter) + /* Secure Encrypted Virtualization command */ enum sev_cmd_id { /* Guest initialization commands */ |