TencentOS-kernel/virt/kvm/arm
Zenghui Yu fd66dcfbc9 KVM: arm64: vgic-v3: Drop the reporting of GICR_TYPER.Last for userspace
commit 23bde34771f1ea92fb5e6682c0d8c04304d34b3b upstream.

It was recently reported that if GICR_TYPER is accessed before the RD base
address is set, we'll suffer from the unset @rdreg dereferencing. Oops...

	gpa_t last_rdist_typer = rdreg->base + GICR_TYPER +
			(rdreg->free_index - 1) * KVM_VGIC_V3_REDIST_SIZE;

It's "expected" that users will access registers in the redistributor if
the RD has been properly configured (e.g., the RD base address is set). But
it hasn't yet been covered by the existing documentation.

Per discussion on the list [1], the reporting of the GICR_TYPER.Last bit
for userspace never actually worked. And it's difficult for us to emulate
it correctly given that userspace has the flexibility to access it any
time. Let's just drop the reporting of the Last bit for userspace for now
(userspace should have full knowledge about it anyway) and it at least
prevents kernel from panic ;-)

[1] https://lore.kernel.org/kvmarm/c20865a267e44d1e2c0d52ce4e012263@kernel.org/

Fixes: ba7b3f1275fd ("KVM: arm/arm64: Revisit Redistributor TYPER last bit computation")
Reported-by: Keqian Zhu <zhukeqian1@huawei.com>
Signed-off-by: Zenghui Yu <yuzenghui@huawei.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Reviewed-by: Eric Auger <eric.auger@redhat.com>
Link: https://lore.kernel.org/r/20201117151629.1738-1-yuzenghui@huawei.com
Cc: stable@vger.kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-03-16 16:41:35 +08:00
..
hyp KVM: arm64: Fix 32bit PC wrap-around 2021-03-16 16:27:39 +08:00
vgic KVM: arm64: vgic-v3: Drop the reporting of GICR_TYPER.Last for userspace 2021-03-16 16:41:35 +08:00
aarch32.c KVM: arm64: Synchronize sysreg state on injecting an AArch32 exception 2021-03-16 16:29:14 +08:00
arch_timer.c Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces. 2021-03-16 11:01:34 +08:00
arm.c KVM: arm64: Save the host's PtrAuth keys in non-preemptible context 2021-03-16 16:29:14 +08:00
mmio.c KVM: arm64: Assume write fault on S1PTW permission fault on instruction fetch 2021-03-16 16:37:40 +08:00
mmu.c KVM: arm64: Force PTE mapping on fault resulting in a device mapping 2021-03-16 16:40:33 +08:00
perf.c Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces. 2021-03-16 11:01:34 +08:00
pmu.c Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces. 2021-03-16 11:01:34 +08:00
psci.c KVM: arm64: ARM_SMCCC_ARCH_WORKAROUND_1 doesn't return SMCCC_RET_NOT_REQUIRED 2021-03-16 16:40:40 +08:00
trace.h Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces. 2021-03-16 11:01:34 +08:00