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| author | Vitaly Kuznetsov <vkuznets@redhat.com> | 2020-05-25 17:41:20 +0300 |
|---|---|---|
| committer | Paolo Bonzini <pbonzini@redhat.com> | 2020-06-01 11:26:07 +0300 |
| commit | 2635b5c4a0e407b84f68e188c719f28ba0e9ae1b (patch) | |
| tree | 7ce893331dea17b655113e3ed7640f7aa8462bf8 /arch/x86/include/uapi | |
| parent | 0958f0cefede403037653e44de0e3332d10b0e1a (diff) | |
| download | linux-2635b5c4a0e407b84f68e188c719f28ba0e9ae1b.tar.xz | |
KVM: x86: interrupt based APF 'page ready' event delivery
Concerns were expressed around APF delivery via synthetic #PF exception as
in some cases such delivery may collide with real page fault. For 'page
ready' notifications we can easily switch to using an interrupt instead.
Introduce new MSR_KVM_ASYNC_PF_INT mechanism and deprecate the legacy one.
One notable difference between the two mechanisms is that interrupt may not
get handled immediately so whenever we would like to deliver next event
(regardless of its type) we must be sure the guest had read and cleared
previous event in the slot.
While on it, get rid on 'type 1/type 2' names for APF events in the
documentation as they are causing confusion. Use 'page not present'
and 'page ready' everywhere instead.
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Message-Id: <20200525144125.143875-6-vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Diffstat (limited to 'arch/x86/include/uapi')
| -rw-r--r-- | arch/x86/include/uapi/asm/kvm_para.h | 12 |
1 files changed, 11 insertions, 1 deletions
diff --git a/arch/x86/include/uapi/asm/kvm_para.h b/arch/x86/include/uapi/asm/kvm_para.h index d1cd5c0f431a..1d37d616b1fc 100644 --- a/arch/x86/include/uapi/asm/kvm_para.h +++ b/arch/x86/include/uapi/asm/kvm_para.h @@ -50,6 +50,7 @@ #define MSR_KVM_STEAL_TIME 0x4b564d03 #define MSR_KVM_PV_EOI_EN 0x4b564d04 #define MSR_KVM_POLL_CONTROL 0x4b564d05 +#define MSR_KVM_ASYNC_PF_INT 0x4b564d06 struct kvm_steal_time { __u64 steal; @@ -81,6 +82,11 @@ struct kvm_clock_pairing { #define KVM_ASYNC_PF_ENABLED (1 << 0) #define KVM_ASYNC_PF_SEND_ALWAYS (1 << 1) #define KVM_ASYNC_PF_DELIVERY_AS_PF_VMEXIT (1 << 2) +#define KVM_ASYNC_PF_DELIVERY_AS_INT (1 << 3) + +/* MSR_KVM_ASYNC_PF_INT */ +#define KVM_ASYNC_PF_VEC_MASK GENMASK(7, 0) + /* Operations for KVM_HC_MMU_OP */ #define KVM_MMU_OP_WRITE_PTE 1 @@ -112,8 +118,12 @@ struct kvm_mmu_op_release_pt { #define KVM_PV_REASON_PAGE_READY 2 struct kvm_vcpu_pv_apf_data { + /* Used for 'page not present' events delivered via #PF */ __u32 flags; - __u32 token; /* Used for page ready notification only */ + + /* Used for 'page ready' events delivered via interrupt notification */ + __u32 token; + __u8 pad[56]; __u32 enabled; }; |