On Thu, Jul 19, 2018 at 01:11:17PM +0200, Andrew Jones wrote: > On Thu, Jun 21, 2018 at 03:57:35PM +0100, Dave Martin wrote: > > This patch adds the necessary support for context switching ZCR_EL1 > > for each vcpu. > > > > The ID_AA64PFR0_EL1 emulation code is updated to expose the > > presence of SVE to the guest if appropriate, and ioctl() access to > > ZCR_EL1 is also added. > > > > In the context switch code itself, ZCR_EL1 is context switched if > > the host is SVE-capable, irrespectively for now of whether SVE is > > exposed to the guest or not. Adding a dynamic vcpu_has_sve() check > > may lose as much performance as would be gained in this simple > > case. > > > > Signed-off-by: Dave Martin <Dave.Martin@xxxxxxx> [...] > > #define SCTLR_ELx_IESB (1 << 21) > > diff --git a/arch/arm64/kvm/hyp/sysreg-sr.c b/arch/arm64/kvm/hyp/sysreg-sr.c > > index 35bc168..0f4046a 100644 > > --- a/arch/arm64/kvm/hyp/sysreg-sr.c > > +++ b/arch/arm64/kvm/hyp/sysreg-sr.c > > @@ -21,6 +21,7 @@ > > #include <asm/kvm_asm.h> > > #include <asm/kvm_emulate.h> > > #include <asm/kvm_hyp.h> > > +#include <asm/sysreg.h> > > > > /* > > * Non-VHE: Both host and guest must save everything. > > @@ -57,6 +58,8 @@ static void __hyp_text __sysreg_save_el1_state(struct kvm_cpu_context *ctxt) > > ctxt->sys_regs[SCTLR_EL1] = read_sysreg_el1(sctlr); > > ctxt->sys_regs[ACTLR_EL1] = read_sysreg(actlr_el1); > > ctxt->sys_regs[CPACR_EL1] = read_sysreg_el1(cpacr); > > + if (system_supports_sve()) /* implies has_vhe() */ > > + ctxt->sys_regs[ZCR_EL1] = read_sysreg_s(SYS_ZCR_EL12); > > ctxt->sys_regs[TTBR0_EL1] = read_sysreg_el1(ttbr0); > > ctxt->sys_regs[TTBR1_EL1] = read_sysreg_el1(ttbr1); > > ctxt->sys_regs[TCR_EL1] = read_sysreg_el1(tcr); > > @@ -129,6 +132,8 @@ static void __hyp_text __sysreg_restore_el1_state(struct kvm_cpu_context *ctxt) > > write_sysreg_el1(ctxt->sys_regs[SCTLR_EL1], sctlr); > > write_sysreg(ctxt->sys_regs[ACTLR_EL1], actlr_el1); > > write_sysreg_el1(ctxt->sys_regs[CPACR_EL1], cpacr); > > + if (system_supports_sve()) /* implies has_vhe() */ > > + write_sysreg_s(ctxt->sys_regs[ZCR_EL1], SYS_ZCR_EL12); > > I feel like the ZCR_EL12 save/restores are out of place, as these > functions are shared by non-VHE and VHE. Maybe they should be > moved to the VHE callers? Hmmm, you're right -- it did look a bit odd at the time. I think they should move to the vhe-specific paths as you suggest. I'll change this for the next spin of the series. Cheers ---Dave _______________________________________________ kvmarm mailing list kvmarm@xxxxxxxxxxxxxxxxxxxxx https://lists.cs.columbia.edu/mailman/listinfo/kvmarm
