Oliver Upton 810f9b6f0a KVM: arm64: Handle PSCI resets before userspace touches vCPU state ... [ Upstream commit 6826c6849b46aaa91300201213701eb861af4ba0 ] The CPU_ON PSCI call takes a payload that KVM uses to configure a destination vCPU to run. This payload is non-architectural state and not exposed through any existing UAPI. Effectively, we have a race between CPU_ON and userspace saving/restoring a guest: if the target vCPU isn't ran again before the VMM saves its state, the requested PC and context ID are lost. When restored, the target vCPU will be runnable and start executing at its old PC. We can avoid this race by making sure the reset payload is serviced before userspace can access a vCPU's state. Fixes: 358b28f09f ("arm/arm64: KVM: Allow a VCPU to fully reset itself") Signed-off-by: Oliver Upton <oupton@google.com> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20210818202133.1106786-3-oupton@google.com Signed-off-by: Sasha Levin <sashal@kernel.org>		2021-09-22 12:26:45 +02:00
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kvm	KVM: arm64: Handle PSCI resets before userspace touches vCPU state	2021-09-22 12:26:45 +02:00
lib	treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500	2019-06-19 17:09:55 +02:00
Makefile	treewide: Add SPDX license identifier - Makefile/Kconfig	2019-05-21 10:50:46 +02:00