[PATCH v5 1/2] KVM: Switch 'requests' to be 64-bit (explicitly)

From: KarimAllah Ahmed
Date: Tue Jul 10 2018 - 05:27:40 EST


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.

Cc: Paolo Bonzini <pbonzini@xxxxxxxxxx>
Cc: Radim KrÄmÃÅ <rkrcmar@xxxxxxxxxx>
Cc: kvm@xxxxxxxxxxxxxxx
Cc: linux-kernel@xxxxxxxxxxxxxxx
Reviewed-by: Jim Mattson <jmattson@xxxxxxxxxx>
Signed-off-by: KarimAllah Ahmed <karahmed@xxxxxxxxx>
---
v1 -> v2:
- Use FIELD_SIZEOF
---
include/linux/kvm_host.h | 10 +++++-----
1 file changed, 5 insertions(+), 5 deletions(-)

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)
--
2.7.4