| Message ID | 1531214840-24686-1-git-send-email-karahmed@amazon.de (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
2018-07-10 11:27+0200, KarimAllah Ahmed: > Switch 'requests' to be explicitly 64-bit and update BUILD_BUG_ON check to > use the size of "requests" instead of the hard-coded '32'. > > That gives us a bit more room again for arch-specific requests as we > already ran out of space for x86 due to the hard-coded check. > > The only exception here is ARM32 as it is still 32-bits. What do you mean? I think we're just going to slow down kvm_request_pending() on 32 bit architectures. > Cc: Paolo Bonzini <pbonzini@redhat.com> > Cc: Radim Krčmář <rkrcmar@redhat.com> > Cc: kvm@vger.kernel.org > Cc: linux-kernel@vger.kernel.org > Reviewed-by: Jim Mattson <jmattson@google.com> > Signed-off-by: KarimAllah Ahmed <karahmed@amazon.de> > --- > v1 -> v2: > - Use FIELD_SIZEOF > --- > diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h > @@ -130,7 +130,7 @@ static inline bool is_error_page(struct page *page) > #define KVM_REQUEST_ARCH_BASE 8 Now that the base is easily moveable, we could also lower it to 4 and get few more arch flags. Bumping requests to 64 bits is probably inevitable and this patch looks good. In v4, you have proposed the bitmap-array solution that would easily allow more than 64 requests -- was the problem that possible implementations of kvm_request_pending were not as efficient for current amount of requests? Thanks. > #define KVM_ARCH_REQ_FLAGS(nr, flags) ({ \ > - BUILD_BUG_ON((unsigned)(nr) >= 32 - KVM_REQUEST_ARCH_BASE); \ > + BUILD_BUG_ON((unsigned)(nr) >= (FIELD_SIZEOF(struct kvm_vcpu, requests) * 8) - KVM_REQUEST_ARCH_BASE); \ > (unsigned)(((nr) + KVM_REQUEST_ARCH_BASE) | (flags)); \ > }) > #define KVM_ARCH_REQ(nr) KVM_ARCH_REQ_FLAGS(nr, 0)
diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h index 4ee7bc5..64518a1 100644 --- a/include/linux/kvm_host.h +++ b/include/linux/kvm_host.h @@ -130,7 +130,7 @@ static inline bool is_error_page(struct page *page) #define KVM_REQUEST_ARCH_BASE 8 #define KVM_ARCH_REQ_FLAGS(nr, flags) ({ \ - BUILD_BUG_ON((unsigned)(nr) >= 32 - KVM_REQUEST_ARCH_BASE); \ + BUILD_BUG_ON((unsigned)(nr) >= (FIELD_SIZEOF(struct kvm_vcpu, requests) * 8) - KVM_REQUEST_ARCH_BASE); \ (unsigned)(((nr) + KVM_REQUEST_ARCH_BASE) | (flags)); \ }) #define KVM_ARCH_REQ(nr) KVM_ARCH_REQ_FLAGS(nr, 0) @@ -224,7 +224,7 @@ struct kvm_vcpu { int vcpu_id; int srcu_idx; int mode; - unsigned long requests; + u64 requests; unsigned long guest_debug; int pre_pcpu; @@ -1124,7 +1124,7 @@ 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 & KVM_REQUEST_MASK, &vcpu->requests); + set_bit(req & KVM_REQUEST_MASK, (void *)&vcpu->requests); } static inline bool kvm_request_pending(struct kvm_vcpu *vcpu) @@ -1134,12 +1134,12 @@ static inline bool kvm_request_pending(struct kvm_vcpu *vcpu) static inline bool kvm_test_request(int req, struct kvm_vcpu *vcpu) { - return test_bit(req & KVM_REQUEST_MASK, &vcpu->requests); + return test_bit(req & KVM_REQUEST_MASK, (void *)&vcpu->requests); } static inline void kvm_clear_request(int req, struct kvm_vcpu *vcpu) { - clear_bit(req & KVM_REQUEST_MASK, &vcpu->requests); + clear_bit(req & KVM_REQUEST_MASK, (void *)&vcpu->requests); } static inline bool kvm_check_request(int req, struct kvm_vcpu *vcpu)