3a7c8fafd1b42adea229fd204132f6a2fb3cd2d9 ("x86/kvm: Restrict
ASYNC_PF to user space") stopped setting KVM_ASYNC_PF_SEND_ALWAYS in
Linux guests. While the flag can still be used by legacy guests, the
mechanism is best effort so KVM is not obliged to use it.
Suggested-by: Vitaly Kuznetsov <vkuznets@xxxxxxxxxx>
Signed-off-by: Nikita Kalyazin <kalyazin@xxxxxxxxxx>
---
Documentation/virt/kvm/x86/msr.rst | 11 +++++------
arch/x86/include/asm/kvm_host.h | 1 -
arch/x86/include/uapi/asm/kvm_para.h | 2 +-
arch/x86/kvm/x86.c | 4 +---
4 files changed, 7 insertions(+), 11 deletions(-)
diff --git a/Documentation/virt/kvm/x86/msr.rst b/Documentation/virt/kvm/x86/msr.rst
index 3aecf2a70e7b..b3bbc12b5d03 100644
--- a/Documentation/virt/kvm/x86/msr.rst
+++ b/Documentation/virt/kvm/x86/msr.rst
@@ -208,12 +208,11 @@ data:
Bits 5-4 of the MSR are reserved and should be zero. Bit 0 is set to 1
when asynchronous page faults are enabled on the vcpu, 0 when disabled.
- Bit 1 is 1 if asynchronous page faults can be injected when vcpu is in
- cpl == 0. Bit 2 is 1 if asynchronous page faults are delivered to L1 as
- #PF vmexits. Bit 2 can be set only if KVM_FEATURE_ASYNC_PF_VMEXIT is
- present in CPUID. Bit 3 enables interrupt based delivery of 'page ready'
- events. Bit 3 can only be set if KVM_FEATURE_ASYNC_PF_INT is present in
- CPUID.
+ Bit 1 is reserved and should be zero. Bit 2 is 1 if asynchronous page
+ faults are delivered to L1 as #PF vmexits. Bit 2 can be set only if
+ KVM_FEATURE_ASYNC_PF_VMEXIT is present in CPUID. Bit 3 enables
+ interrupt based delivery of 'page ready' events. Bit 3 can only be set
+ if KVM_FEATURE_ASYNC_PF_INT is present in CPUID.
'Page not present' events are currently always delivered as synthetic
#PF exception. During delivery of these events APF CR2 register contains
diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index e159e44a6a1b..8ce00b17316f 100644
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -975,7 +975,6 @@ struct kvm_vcpu_arch {
u64 msr_int_val; /* MSR_KVM_ASYNC_PF_INT */
u16 vec;
u32 id;
- bool send_user_only;
u32 host_apf_flags;
bool delivery_as_pf_vmexit;
bool pageready_pending;
diff --git a/arch/x86/include/uapi/asm/kvm_para.h b/arch/x86/include/uapi/asm/kvm_para.h
index a1efa7907a0b..5558a1ec3dc9 100644
--- a/arch/x86/include/uapi/asm/kvm_para.h
+++ b/arch/x86/include/uapi/asm/kvm_para.h
@@ -87,7 +87,7 @@ struct kvm_clock_pairing {
#define KVM_MAX_MMU_OP_BATCH 32
#define KVM_ASYNC_PF_ENABLED (1 << 0)
-#define KVM_ASYNC_PF_SEND_ALWAYS (1 << 1)
+#define KVM_ASYNC_PF_SEND_ALWAYS (1 << 1) /* deprecated */
#define KVM_ASYNC_PF_DELIVERY_AS_PF_VMEXIT (1 << 2)
#define KVM_ASYNC_PF_DELIVERY_AS_INT (1 << 3)
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 2e713480933a..8f784f07d423 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -3558,7 +3558,6 @@ static int kvm_pv_enable_async_pf(struct kvm_vcpu *vcpu, u64 data)
sizeof(u64)))
return 1;
- vcpu->arch.apf.send_user_only = !(data & KVM_ASYNC_PF_SEND_ALWAYS);
vcpu->arch.apf.delivery_as_pf_vmexit = data & KVM_ASYNC_PF_DELIVERY_AS_PF_VMEXIT;
kvm_async_pf_wakeup_all(vcpu);
@@ -13361,8 +13360,7 @@ static bool kvm_can_deliver_async_pf(struct kvm_vcpu *vcpu)
if (!kvm_pv_async_pf_enabled(vcpu))
return false;
- if (vcpu->arch.apf.send_user_only &&
- kvm_x86_call(get_cpl)(vcpu) == 0)
+ if (kvm_x86_call(get_cpl)(vcpu) == 0)
return false;
if (is_guest_mode(vcpu)) {
--
2.40.1
