Commit 83bb2c1a authored Nov 16, 2021 by Marc Zyngier

KVM: arm64: Save PSTATE early on exit



In order to be able to use primitives such as vcpu_mode_is_32bit(),
we need to synchronize the guest PSTATE. However, this is currently
done deep into the bowels of the world-switch code, and we do have
helpers evaluating this much earlier (__vgic_v3_perform_cpuif_access
and handle_aarch32_guest, for example).

Move the saving of the guest pstate into the early fixups, which
cures the first issue. The second one will be addressed separately.

Tested-by: Fuad Tabba <tabba@google.com>
Reviewed-by: Fuad Tabba <tabba@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>

parent fa55b7dc

arch/arm64/kvm/hyp/include/hyp/switch.h

+6 −0

Original line number	Diff line number	Diff line
		@@ -429,6 +429,12 @@ static inline bool kvm_hyp_handle_exit(struct kvm_vcpu vcpu, u64 exit_code)
		*/
		static inline bool fixup_guest_exit(struct kvm_vcpu vcpu, u64 exit_code)
		{
		/*
		* Save PSTATE early so that we can evaluate the vcpu mode
		* early on.
		*/
		vcpu->arch.ctxt.regs.pstate = read_sysreg_el2(SYS_SPSR);

		if (ARM_EXCEPTION_CODE(*exit_code) != ARM_EXCEPTION_IRQ)
		vcpu->arch.fault.esr_el2 = read_sysreg_el2(SYS_ESR);

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

+6 −1

Original line number	Diff line number	Diff line
		@@ -70,6 +70,11 @@ static inline void __sysreg_save_el1_state(struct kvm_cpu_context *ctxt)
		static inline void __sysreg_save_el2_return_state(struct kvm_cpu_context *ctxt)
		{
		ctxt->regs.pc = read_sysreg_el2(SYS_ELR);
		/*
		* Guest PSTATE gets saved at guest fixup time in all
		* cases. We still need to handle the nVHE host side here.
		*/
		if (!has_vhe() && ctxt->__hyp_running_vcpu)
		ctxt->regs.pstate = read_sysreg_el2(SYS_SPSR);

		if (cpus_have_final_cap(ARM64_HAS_RAS_EXTN))