Cluster x2APIC cannot work without KVM's x2apic API when the maximal
APIC ID is greater than 8 and only KVM's LAPIC can support x2APIC, so we
forbid other APICs and also the old KVM case with less than 9, to
simplify the code.
There is no point in enabling EIM in forbidden APICs, so we keep it
enabled only for the KVM APIC; unconditionally, because making the
option depend on KVM version would be a maintanance burden.
Old QEMUs would enable eim whenever intremap was on, which would trick
guests into thinking that they can enable cluster x2APIC even if any
interrupt destination would get clamped to 8 bits.
Depending on your configuration, QEMU could notice that the destination
LAPIC is not present and report it with a very non-obvious:
KVM: injection failed, MSI lost (Operation not permitted)
Or the guest could say something about unexpected interrupts, because
clamping leads to aliasing so interrupts were being delivered to
incorrect VCPUs.
KVM_X2APIC_API is the feature that allows us to enable EIM for KVM.
QEMU 2.7 allowed EIM whenever interrupt remapping was enabled. In order
to keep backward compatibility, we again allow guests to misbehave in
non-obvious ways, and make it the default for old machine types.
A user can enable the buggy mode it with "x-buggy-eim=on".
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
Reviewed-by: Eduardo Habkost <ehabkost@redhat.com>
Reviewed-by: Peter Xu <peterx@redhat.com>
Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
Clean up includes so that osdep.h is included first and headers
which it implies are not included manually.
This commit was created with scripts/clean-includes.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Message-id: 1453832250-766-11-git-send-email-peter.maydell@linaro.org
The property can take values on, off or auto. The default is "off"
for KVM and pre-2.4 machines, otherwise "auto" (which makes it
available on TCG or on new-enough kernels).
Acked-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Fix build failures with clang when KVM is not enabled by
providing a stub version of kvm_arch_get_supported_cpuid().
We retain the compile time check that this function isn't
called when CONFIG_KVM is not set by guarding the stub with
ifndef __OPTIMIZE__ (we assume that an optimizing build will
do sufficient constant folding and dead code elimination to
remove the calls before linking).
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
kvm_allows_irq0_override() is a totally x86 specific concept:
move it to the target-specific source file where it belongs.
This means we need a new header file for the prototype:
kvm_i386.h, in line with the existing kvm_ppc.h.
While we are moving it, fix the return type to be 'bool' rather
than 'int'.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Avi Kivity <avi@redhat.com>
