linux/arch/arm64
Marc Zyngier 5bfa685e62 KVM: arm64: vgic: Read HW interrupt pending state from the HW
It appears that a read access to GIC[DR]_I[CS]PENDRn doesn't always
result in the pending interrupts being accurately reported if they are
mapped to a HW interrupt. This is particularily visible when acking
the timer interrupt and reading the GICR_ISPENDR1 register immediately
after, for example (the interrupt appears as not-pending while it really
is...).

This is because a HW interrupt has its 'active and pending state' kept
in the *physical* distributor, and not in the virtual one, as mandated
by the spec (this is what allows the direct deactivation). The virtual
distributor only caries the pending and active *states* (note the
plural, as these are two independent and non-overlapping states).

Fix it by reading the HW state back, either from the timer itself or
from the distributor if necessary.

Reported-by: Ricardo Koller <ricarkol@google.com>
Tested-by: Ricardo Koller <ricarkol@google.com>
Reviewed-by: Ricardo Koller <ricarkol@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20220208123726.3604198-1-maz@kernel.org
2022-02-11 11:01:12 +00:00
..
boot sound updates for 5.17-rc1 2022-01-14 14:55:38 +01:00
configs arm64: defconfig: Enable Samsung I2C driver 2021-12-21 12:18:44 +01:00
crypto arm64: Add macro version of the BTI instruction 2021-12-14 18:12:58 +00:00
hyperv
include coresight: trbe: Workaround Cortex-A510 erratas 2022-01-28 16:14:06 +00:00
kernel KVM: arm64: Workaround Cortex-A510's single-step and PAC trap errata 2022-02-03 09:22:30 +00:00
kvm KVM: arm64: vgic: Read HW interrupt pending state from the HW 2022-02-11 11:01:12 +00:00
lib Merge branches 'for-next/misc', 'for-next/cache-ops-dzp', 'for-next/stacktrace', 'for-next/xor-neon', 'for-next/kasan', 'for-next/armv8_7-fp', 'for-next/atomics', 'for-next/bti', 'for-next/sve', 'for-next/kselftest' and 'for-next/kcsan', remote-tracking branch 'arm64/for-next/perf' into for-next/core 2022-01-05 18:14:32 +00:00
mm arm64: extable: fix load_unaligned_zeropad() reg indices 2022-01-26 18:58:12 +00:00
net bpf, arm64: Use emit_addr_mov_i64() for BPF_PSEUDO_FUNC 2022-01-05 20:43:08 +01:00
tools KVM: arm64: Workaround Cortex-A510's single-step and PAC trap errata 2022-02-03 09:22:30 +00:00
xen xen: allow pv-only hypercalls only with CONFIG_XEN_PV 2021-11-02 08:11:01 -05:00
Kbuild
Kconfig KVM: arm64: Workaround Cortex-A510's single-step and PAC trap errata 2022-02-03 09:22:30 +00:00
Kconfig.debug
Kconfig.platforms ARM: SoC updates for v5.17 2022-01-10 08:10:20 -08:00
Makefile arm64/xor: use EOR3 instructions when available 2021-12-14 12:14:26 +00:00