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3 commits

Author SHA1 Message Date
Anup Patel 203a74f35c arm64: KVM: Add Kconfig option for max VCPUs per-Guest
Current max VCPUs per-Guest is set to 4 which is preventing
us from creating a Guest (or VM) with 8 VCPUs on Host (e.g.
X-Gene Storm SOC) with 8 Host CPUs.

The correct value of max VCPUs per-Guest should be same as
the max CPUs supported by GICv2 which is 8 but, increasing
value of max VCPUs per-Guest can make things slower hence
we add Kconfig option to let KVM users select appropriate
max VCPUs per-Guest.

Signed-off-by: Anup Patel <anup.patel@linaro.org>
Signed-off-by: Pranavkumar Sawargaonkar <pranavkumar@linaro.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Git-commit: da7814700a0c408bead58ce4714b7625ffbaade1
Git-repo: git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
Signed-off-by: Ian Maund <imaund@codeaurora.org>
2014-04-17 17:04:56 -07:00
Marc Zyngier 06e55300b2 arm64: KVM: Yield CPU when vcpu executes a WFE
On an (even slightly) oversubscribed system, spinlocks are quickly
becoming a bottleneck, as some vcpus are spinning, waiting for a
lock to be released, while the vcpu holding the lock may not be
running at all.

The solution is to trap blocking WFEs and tell KVM that we're
now spinning. This ensures that other vpus will get a scheduling
boost, allowing the lock to be released more quickly. Also, using
CONFIG_HAVE_KVM_CPU_RELAX_INTERCEPT slightly improves the performance
when the VM is severely overcommited.

Acked-by: Christoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Git-commit: d241aac798eb042e605f78c31a4122e583b2cd13
Git-repo: git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
Signed-off-by: Ian Maund <imaund@codeaurora.org>
2014-02-07 13:49:56 -08:00
Marc Zyngier 13f90a8ffe arm64: KVM: Kconfig integration
Finally plug KVM/arm64 into the config system, making it possible
to enable KVM support on AArch64 CPUs.

Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Git-commit: c3eb5b14449a0949e9764d39374a2ea63faae14f
Git-repo: git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
Signed-off-by: Ian Maund <imaund@codeaurora.org>
2014-02-07 13:49:41 -08:00