KVM: arm64: Avoid reading ID_AA64DFR0_EL1 for debug save/restore

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Similar to other per-CPU profiling/debug features we handle, store the
number of breakpoints/watchpoints in kvm_host_data to avoid reading the
ID register 4 times on every guest entry/exit. And if you're in the
nested virt business that's quite a few avoidable exits to the L0
hypervisor.

Tested-by: James Clark <james.clark@linaro.org>
Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
Link: https://lore.kernel.org/r/20241219224116.3941496-18-oliver.upton@linux.dev
Signed-off-by: Marc Zyngier <maz@kernel.org>

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Oliver Upton 2024-12-19 14:41:14 -08:00 • committed by Marc Zyngier

parent b0ee51033a

commit 8c02c2bbd6

3 changed files with 11 additions and 13 deletions

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4

arch/arm64/include/asm/kvm_host.h

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3

arch/arm64/kvm/debug.c

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17

arch/arm64/kvm/hyp/include/hyp/debug-sr.h

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