On Fri, Jan 28, 2022 at 12:18:25PM +0000, Marc Zyngier wrote: > From: Christoffer Dall <[email protected]> > > We can no longer blindly copy the VCPU's PSTATE into SPSR_EL2 and return > to the guest and vice versa when taking an exception to the hypervisor, > because we emulate virtual EL2 in EL1 and therefore have to translate > the mode field from EL2 to EL1 and vice versa. > > This requires keeping track of the state we enter the guest, for which > we transiently use a dedicated flag. > > Signed-off-by: Marc Zyngier <[email protected]> > --- > arch/arm64/include/asm/kvm_host.h | 1 + > arch/arm64/kvm/hyp/include/hyp/sysreg-sr.h | 19 ++++++++++++++++- > arch/arm64/kvm/hyp/vhe/switch.c | 24 ++++++++++++++++++++++ > 3 files changed, 43 insertions(+), 1 deletion(-) > > diff --git a/arch/arm64/include/asm/kvm_host.h > b/arch/arm64/include/asm/kvm_host.h > index 8fffe2888403..fa253f08e0fd 100644 > --- a/arch/arm64/include/asm/kvm_host.h > +++ b/arch/arm64/include/asm/kvm_host.h > @@ -472,6 +472,7 @@ struct kvm_vcpu_arch { > #define KVM_ARM64_DEBUG_STATE_SAVE_SPE (1 << 12) /* Save SPE context > if active */ > #define KVM_ARM64_DEBUG_STATE_SAVE_TRBE (1 << 13) /* Save TRBE context > if active */ > #define KVM_ARM64_FP_FOREIGN_FPSTATE (1 << 14) > +#define KVM_ARM64_IN_HYP_CONTEXT (1 << 15) /* Guest running in HYP > context */ > > #define KVM_GUESTDBG_VALID_MASK (KVM_GUESTDBG_ENABLE | \ > KVM_GUESTDBG_USE_SW_BP | \ > diff --git a/arch/arm64/kvm/hyp/include/hyp/sysreg-sr.h > b/arch/arm64/kvm/hyp/include/hyp/sysreg-sr.h > index 283f780f5f56..e3689c6ce4cc 100644 > --- a/arch/arm64/kvm/hyp/include/hyp/sysreg-sr.h > +++ b/arch/arm64/kvm/hyp/include/hyp/sysreg-sr.h > @@ -157,9 +157,26 @@ static inline void __sysreg_restore_el1_state(struct > kvm_cpu_context *ctxt, > write_sysreg_el1(ctxt_sys_reg(ctxt, SPSR_EL1), SYS_SPSR); > } > > +/* Read the VCPU state's PSTATE, but translate (v)EL2 to EL1. */ > +static inline u64 to_hw_pstate(const struct kvm_cpu_context *ctxt) > +{ > + u64 mode = ctxt->regs.pstate & (PSR_MODE_MASK | PSR_MODE32_BIT); > + > + switch (mode) { > + case PSR_MODE_EL2t: > + mode = PSR_MODE_EL1t; > + break; > + case PSR_MODE_EL2h: > + mode = PSR_MODE_EL1h; > + break; > + } > + > + return (ctxt->regs.pstate & ~(PSR_MODE_MASK | PSR_MODE32_BIT)) | mode; > +} > +
Wondering if it makes sense to also have the reverse translation as an inline function after the above too, so the two translations are together - but as it's only used (in this patch at least) in switch.c there probably isn't too much point. So: Reviewed-by: Russell King (Oracle) <[email protected]> -- RMK's Patch system: https://www.armlinux.org.uk/developer/patches/ FTTP is here! 40Mbps down 10Mbps up. Decent connectivity at last! _______________________________________________ kvmarm mailing list [email protected] https://lists.cs.columbia.edu/mailman/listinfo/kvmarm
