Zenghui Yu 6276d38cce KVM: arm64: vgic-v3: Drop the reporting of GICR_TYPER.Last for userspace ... commit 23bde34771 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: ba7b3f1275 ("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>		2020-12-02 08:49:46 +01:00
..
arm	KVM: arm64: vgic-v3: Drop the reporting of GICR_TYPER.Last for userspace	2020-12-02 08:49:46 +01:00
Kconfig	KVM: polling: add architecture backend to disable polling	2019-04-26 09:08:17 +02:00
async_pf.c	KVM: x86: Use gpa_t for cr2/gpa to fix TDP support on 32-bit KVM	2020-02-11 04:35:53 -08:00
async_pf.h	treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 504	2019-06-19 17:09:56 +02:00
coalesced_mmio.c	KVM: coalesced_mmio: add bounds checking	2019-09-18 15:56:55 +02:00
coalesced_mmio.h	License cleanup: add SPDX GPL-2.0 license identifier to files with no license	2017-11-02 11:10:55 +01:00
eventfd.c	treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 504	2019-06-19 17:09:56 +02:00
irqchip.c	KVM/arm updates for 5.3	2019-07-11 15:14:16 +02:00
kvm_main.c	KVM: fix overflow of zero page refcount with ksm running	2020-10-01 13:17:31 +02:00
vfio.c	treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500	2019-06-19 17:09:55 +02:00
vfio.h	License cleanup: add SPDX GPL-2.0 license identifier to files with no license	2017-11-02 11:10:55 +01:00