KVM_CAP_IRQFD and KVM_CAP_IRQFD_RESAMPLE checks

Compute kvm_irqfds_allowed by checking the KVM_CAP_IRQFD extension.
Remove direct settings in architecture specific files.

Add a new kvm_resamplefds_allowed variable, initialized by
checking the KVM_CAP_IRQFD_RESAMPLE extension. Add a corresponding
kvm_resamplefds_enabled() function.

A special notice for s390 where KVM_CAP_IRQFD was not immediatly
advirtised when irqfd capability was introduced in the kernel.
KVM_CAP_IRQ_ROUTING was advertised instead.

This was fixed in "KVM: s390: announce irqfd capability",
ebc3226202d5956a5963185222982d435378b899 whereas irqfd support
was brought in 84223598778ba08041f4297fda485df83414d57e,
"KVM: s390: irq routing for adapter interrupts".  Both commits
first appear in 3.15 so there should not be any kernel
version impacted by this QEMU modification.

Signed-off-by: Eric Auger <eric.auger@linaro.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
This commit is contained in:
Eric Auger 2014-10-31 13:38:18 +00:00 committed by Paolo Bonzini
parent 9551ea6991
commit f41389ae3c
6 changed files with 17 additions and 4 deletions

View file

@ -45,6 +45,7 @@ extern bool kvm_async_interrupts_allowed;
extern bool kvm_halt_in_kernel_allowed;
extern bool kvm_eventfds_allowed;
extern bool kvm_irqfds_allowed;
extern bool kvm_resamplefds_allowed;
extern bool kvm_msi_via_irqfd_allowed;
extern bool kvm_gsi_routing_allowed;
extern bool kvm_gsi_direct_mapping;
@ -101,6 +102,15 @@ extern bool kvm_readonly_mem_allowed;
*/
#define kvm_irqfds_enabled() (kvm_irqfds_allowed)
/**
* kvm_resamplefds_enabled:
*
* Returns: true if we can use resamplefds to inject interrupts into
* a KVM CPU (ie the kernel supports resamplefds and we are running
* with a configuration where it is meaningful to use them).
*/
#define kvm_resamplefds_enabled() (kvm_resamplefds_allowed)
/**
* kvm_msi_via_irqfd_enabled:
*