[PATCH AUTOSEL 5.10 02/15] KVM: arm64: Save PSTATE early on exit
From: Sasha Levin <sashal@kernel.org>
Date: 2021-12-06 21:16:11
Also in:
kvmarm, lkml, stable
Subsystem:
arm64 port (aarch64 architecture), kernel virtual machine for arm64 (kvm/arm64), the rest · Maintainers:
Catalin Marinas, Will Deacon, Marc Zyngier, Oliver Upton, Linus Torvalds
From: Marc Zyngier <maz@kernel.org> [ Upstream commit 83bb2c1a01d7127d5adc7d69d7aaa3f7072de2b4 ] 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 <redacted> Reviewed-by: Fuad Tabba <redacted> Signed-off-by: Marc Zyngier <maz@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org> --- arch/arm64/kvm/hyp/include/hyp/switch.h | 6 ++++++ arch/arm64/kvm/hyp/include/hyp/sysreg-sr.h | 7 ++++++- 2 files changed, 12 insertions(+), 1 deletion(-)
diff --git a/arch/arm64/kvm/hyp/include/hyp/switch.h b/arch/arm64/kvm/hyp/include/hyp/switch.h
index 1f875a8f20c47..8116ae1e636a2 100644
--- a/arch/arm64/kvm/hyp/include/hyp/switch.h
+++ b/arch/arm64/kvm/hyp/include/hyp/switch.h@@ -406,6 +406,12 @@ static inline bool __hyp_handle_ptrauth(struct kvm_vcpu *vcpu) */ 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);
diff --git a/arch/arm64/kvm/hyp/include/hyp/sysreg-sr.h b/arch/arm64/kvm/hyp/include/hyp/sysreg-sr.h
index cce43bfe158fa..0eacfb9d17b02 100644
--- a/arch/arm64/kvm/hyp/include/hyp/sysreg-sr.h
+++ b/arch/arm64/kvm/hyp/include/hyp/sysreg-sr.h@@ -54,7 +54,12 @@ 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); - ctxt->regs.pstate = read_sysreg_el2(SYS_SPSR); + /* + * 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)) ctxt_sys_reg(ctxt, DISR_EL1) = read_sysreg_s(SYS_VDISR_EL2);
--
2.33.0
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