Commit 930f7fd6 authored by Radim Krčmář's avatar Radim Krčmář Committed by Paolo Bonzini
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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: default avatarRadim Krčmář <rkrcmar@redhat.com>
Reviewed-by: default avatarAndrew Jones <drjones@redhat.com>
Reviewed-by: default avatarCornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
parent 75aaafb7

arch/arm/include/asm/kvm_host.h

+1 −1
Original line number Diff line number Diff line
@@ -44,7 +44,7 @@ 
#define KVM_MAX_VCPUS VGIC_V2_MAX_CPUS

#endif



#define KVM_REQ_VCPU_EXIT	8

#define KVM_REQ_VCPU_EXIT	(8 | KVM_REQUEST_NO_WAKEUP)



u32 *kvm_vcpu_reg(struct kvm_vcpu *vcpu, u8 reg_num, u32 mode);

int __attribute_const__ kvm_target_cpu(void);

arch/arm64/include/asm/kvm_host.h

+1 −1
Original line number Diff line number Diff line
@@ -41,7 +41,7 @@ 


#define KVM_VCPU_MAX_FEATURES 4



#define KVM_REQ_VCPU_EXIT	8

#define KVM_REQ_VCPU_EXIT	(8 | KVM_REQUEST_NO_WAKEUP)



int __attribute_const__ kvm_target_cpu(void);

int kvm_reset_vcpu(struct kvm_vcpu *vcpu);

arch/x86/include/asm/kvm_host.h

+3 −3
Original line number Diff line number Diff line
@@ -61,10 +61,10 @@ 
#define KVM_REQ_PMI               19

#define KVM_REQ_SMI               20

#define KVM_REQ_MASTERCLOCK_UPDATE 21

#define KVM_REQ_MCLOCK_INPROGRESS 22

#define KVM_REQ_SCAN_IOAPIC       23

#define KVM_REQ_MCLOCK_INPROGRESS (22 | KVM_REQUEST_NO_WAKEUP)

#define KVM_REQ_SCAN_IOAPIC       (23 | KVM_REQUEST_NO_WAKEUP)

#define KVM_REQ_GLOBAL_CLOCK_UPDATE 24

#define KVM_REQ_APIC_PAGE_RELOAD  25

#define KVM_REQ_APIC_PAGE_RELOAD  (25 | KVM_REQUEST_NO_WAKEUP)

#define KVM_REQ_HV_CRASH          26

#define KVM_REQ_IOAPIC_EOI_EXIT   27

#define KVM_REQ_HV_RESET          28

include/linux/kvm_host.h

+7 −5
Original line number Diff line number Diff line
@@ -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)

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