Messages in this thread Patch in this message | | | From | Jiri Slaby <> | Subject | [PATCH 3.12 04/63] ARM: KVM: Fix MPIDR computing to support virtual clusters | Date | Thu, 30 Apr 2015 14:11:33 +0200 |
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From: Marc Zyngier <marc.zyngier@arm.com>
3.12-stable review patch. If anyone has any objections, please let me know.
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commit 2d1d841bd44e24b58a3d3cc4fa793670aaa38fbf upstream.
In order to be able to support more than 4 A7 or A15 CPUs, we need to fix the MPIDR computing to reflect the fact that both A15 and A7 can only exist in clusters of at most 4 CPUs.
Fix the MPIDR computing to allow virtual clusters to be exposed to the guest.
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org> Signed-off-by: Shannon Zhao <shannon.zhao@linaro.org> Signed-off-by: Jiri Slaby <jslaby@suse.cz> --- arch/arm/kvm/coproc_a15.c | 10 ++++++---- 1 file changed, 6 insertions(+), 4 deletions(-)
diff --git a/arch/arm/kvm/coproc_a15.c b/arch/arm/kvm/coproc_a15.c index bbd4b888dbf3..8611c5c45d93 100644 --- a/arch/arm/kvm/coproc_a15.c +++ b/arch/arm/kvm/coproc_a15.c @@ -27,11 +27,13 @@ static void reset_mpidr(struct kvm_vcpu *vcpu, const struct coproc_reg *r) { /* - * Compute guest MPIDR. No need to mess around with different clusters - * but we read the 'U' bit from the underlying hardware directly. + * Compute guest MPIDR. We build a virtual cluster out of the + * vcpu_id, but we read the 'U' bit from the underlying + * hardware directly. */ - vcpu->arch.cp15[c0_MPIDR] = (read_cpuid_mpidr() & MPIDR_SMP_BITMASK) - | vcpu->vcpu_id; + vcpu->arch.cp15[c0_MPIDR] = ((read_cpuid_mpidr() & MPIDR_SMP_BITMASK) | + ((vcpu->vcpu_id >> 2) << MPIDR_LEVEL_BITS) | + (vcpu->vcpu_id & 3)); } #include "coproc.h" -- 2.3.5
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