On 17/06/2020 15:05, Catalin Marinas wrote:
On Wed, Jun 17, 2020 at 01:38:43PM +0100, Steven Price wrote:diff --git a/arch/arm64/kvm/hyp/sysreg-sr.c b/arch/arm64/kvm/hyp/sysreg-sr.c index 75b1925763f1..6ecee1528566 100644 --- a/arch/arm64/kvm/hyp/sysreg-sr.c +++ b/arch/arm64/kvm/hyp/sysreg-sr.c @@ -26,6 +26,12 @@ static void __hyp_text __sysreg_save_common_state(struct kvm_cpu_context *ctxt) { ctxt->sys_regs[MDSCR_EL1] = read_sysreg(mdscr_el1); + if (system_supports_mte()) { + ctxt->sys_regs[RGSR_EL1] = read_sysreg_s(SYS_RGSR_EL1); + ctxt->sys_regs[GCR_EL1] = read_sysreg_s(SYS_GCR_EL1); + ctxt->sys_regs[TFSRE0_EL1] = read_sysreg_s(SYS_TFSRE0_EL1); + ctxt->sys_regs[TFSR_EL1] = read_sysreg_s(SYS_TFSR_EL1); + }TFSR_EL1 is not a common register as we have the TFSR_EL2 as well. So you'd have to access it as read_sysreg_el1(SYS_TFSR) so that, in the VHE case, it generates TFSR_EL12, otherwise you just save the host register.
Ah, thanks for pointing that out - I'd got myself confused with the whole VHE _EL12 registers. I'd managed to miss that TFSR is banked.
Also, since TFSR*_EL1 can be set asynchronously, I think we need to set the SCTLR_EL2.ITFSB bit so that the register update is synchronised on entry to EL2. With VHE we get this automatically as part of SCTLR_EL1_SET but it turns out that we have another SCTLR_ELx_FLAGS macro for the non-VHE case (why not calling this SCTLR_EL2_* I have no idea).
I hadn't noticed that there was a different set for the non-VHE case which was missing ITFSB - I'll update that.
Thanks, Steve
/* * The host arm64 Linux uses sp_el0 to point to 'current' and it must @@ -99,6 +105,12 @@ NOKPROBE_SYMBOL(sysreg_save_guest_state_vhe); static void __hyp_text __sysreg_restore_common_state(struct kvm_cpu_context *ctxt) { write_sysreg(ctxt->sys_regs[MDSCR_EL1], mdscr_el1); + if (system_supports_mte()) { + write_sysreg_s(ctxt->sys_regs[RGSR_EL1], SYS_RGSR_EL1); + write_sysreg_s(ctxt->sys_regs[GCR_EL1], SYS_GCR_EL1); + write_sysreg_s(ctxt->sys_regs[TFSRE0_EL1], SYS_TFSRE0_EL1); + write_sysreg_s(ctxt->sys_regs[TFSR_EL1], SYS_TFSR_EL1); + }Similarly here, you override the TFSR_EL2 with VHE enabled.
