diff options
| author | Radim Krčmář <rkrcmar@redhat.com> | 2017-04-26 23:32:22 +0300 |
|---|---|---|
| committer | Paolo Bonzini <pbonzini@redhat.com> | 2017-04-27 15:13:57 +0300 |
| commit | 930f7fd6da77ed9476a538345513460fd304aaf5 (patch) | |
| tree | 8d8c53534dc4828e76e3d8daf4aea09a3cc4abe3 /include/linux/kvm_host.h | |
| parent | 75aaafb79f73516b69d5639ad30a72d72e75c8b4 (diff) | |
| download | linux-930f7fd6da77ed9476a538345513460fd304aaf5.tar.xz | |
KVM: mark requests that do not need a wakeup
Some operations must ensure that the guest is not running with stale
data, but if the guest is halted, then the update can wait until another
event happens. kvm_make_all_requests() currently doesn't wake up, so we
can mark all requests used with it.
First 8 bits were arbitrarily reserved for request numbers.
Most uses of requests have the request type as a constant, so a compiler
will optimize the '&'.
An alternative would be to have an inline function that would return
whether the request needs a wake-up or not, but I like this one better
even though it might produce worse assembly.
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
Reviewed-by: Andrew Jones <drjones@redhat.com>
Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Diffstat (limited to 'include/linux/kvm_host.h')
| -rw-r--r-- | include/linux/kvm_host.h | 12 |
1 files changed, 7 insertions, 5 deletions
diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h index 374fa92c7657..a805ddcb7eb0 100644 --- a/include/linux/kvm_host.h +++ b/include/linux/kvm_host.h @@ -115,12 +115,14 @@ static inline bool is_error_page(struct page *page) return IS_ERR(page); } +#define KVM_REQUEST_MASK GENMASK(7,0) +#define KVM_REQUEST_NO_WAKEUP BIT(8) /* * Architecture-independent vcpu->requests bit members * Bits 4-7 are reserved for more arch-independent bits. */ -#define KVM_REQ_TLB_FLUSH 0 -#define KVM_REQ_MMU_RELOAD 1 +#define KVM_REQ_TLB_FLUSH (0 | KVM_REQUEST_NO_WAKEUP) +#define KVM_REQ_MMU_RELOAD (1 | KVM_REQUEST_NO_WAKEUP) #define KVM_REQ_PENDING_TIMER 2 #define KVM_REQ_UNHALT 3 @@ -1076,17 +1078,17 @@ static inline void kvm_make_request(int req, struct kvm_vcpu *vcpu) * caller. Paired with the smp_mb__after_atomic in kvm_check_request. */ smp_wmb(); - set_bit(req, &vcpu->requests); + set_bit(req & KVM_REQUEST_MASK, &vcpu->requests); } static inline bool kvm_test_request(int req, struct kvm_vcpu *vcpu) { - return test_bit(req, &vcpu->requests); + return test_bit(req & KVM_REQUEST_MASK, &vcpu->requests); } static inline void kvm_clear_request(int req, struct kvm_vcpu *vcpu) { - clear_bit(req, &vcpu->requests); + clear_bit(req & KVM_REQUEST_MASK, &vcpu->requests); } static inline bool kvm_check_request(int req, struct kvm_vcpu *vcpu) |