| Message ID | 20190523103502.25925-8-sudeep.holla@arm.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | arm64: KVM: add SPE profiling support for guest | expand |
Hi Sudeep, On 23/05/2019 11:34, Sudeep Holla wrote: > If we enable profiling buffer controls at EL1 generate a trap exception > to EL2, it also changes profiling buffer to use EL1&0 stage 1 translation > regime in case of VHE. To support SPE both in the guest and host, we > need to first stop profiling and flush the profiling buffers before > we activate/switch vm or enable/disable the traps. > > In prepartion to do that, lets split the debug save restore functionality > into 4 steps: > 1. debug_save_host_context - saves the host context > 2. debug_restore_guest_context - restore the guest context > 3. debug_save_guest_context - saves the guest context > 4. debug_restore_host_context - restores the host context > > Lets rename existing __debug_switch_to_{host,guest} to make sure it's > aligned to the above and just add the place holders for new ones getting > added here as we need them to support SPE in guests. > > Signed-off-by: Sudeep Holla <sudeep.holla@arm.com> > --- > arch/arm64/include/asm/kvm_hyp.h | 6 ++++-- > arch/arm64/kvm/hyp/debug-sr.c | 25 ++++++++++++++++--------- > arch/arm64/kvm/hyp/switch.c | 12 ++++++++---- > 3 files changed, 28 insertions(+), 15 deletions(-) > > diff --git a/arch/arm64/include/asm/kvm_hyp.h b/arch/arm64/include/asm/kvm_hyp.h > index 782955db61dd..1c5ed80fcbda 100644 > --- a/arch/arm64/include/asm/kvm_hyp.h > +++ b/arch/arm64/include/asm/kvm_hyp.h > @@ -164,8 +164,10 @@ void sysreg_restore_guest_state_vhe(struct kvm_cpu_context *ctxt); > void __sysreg32_save_state(struct kvm_vcpu *vcpu); > void __sysreg32_restore_state(struct kvm_vcpu *vcpu); > > -void __debug_switch_to_guest(struct kvm_vcpu *vcpu); > -void __debug_switch_to_host(struct kvm_vcpu *vcpu); > +void __debug_save_host_context(struct kvm_vcpu *vcpu); > +void __debug_restore_guest_context(struct kvm_vcpu *vcpu); > +void __debug_save_guest_context(struct kvm_vcpu *vcpu); > +void __debug_restore_host_context(struct kvm_vcpu *vcpu); > > void __fpsimd_save_state(struct user_fpsimd_state *fp_regs); > void __fpsimd_restore_state(struct user_fpsimd_state *fp_regs); > diff --git a/arch/arm64/kvm/hyp/debug-sr.c b/arch/arm64/kvm/hyp/debug-sr.c > index fa51236ebcb3..618884df1dc4 100644 > --- a/arch/arm64/kvm/hyp/debug-sr.c > +++ b/arch/arm64/kvm/hyp/debug-sr.c > @@ -149,20 +149,13 @@ static void __hyp_text __debug_restore_state(struct kvm_vcpu *vcpu, > write_sysreg(ctxt->sys_regs[MDCCINT_EL1], mdccint_el1); > } > > -void __hyp_text __debug_switch_to_guest(struct kvm_vcpu *vcpu) > +void __hyp_text __debug_restore_guest_context(struct kvm_vcpu *vcpu) > { > struct kvm_cpu_context *host_ctxt; > struct kvm_cpu_context *guest_ctxt; > struct kvm_guest_debug_arch *host_dbg; > struct kvm_guest_debug_arch *guest_dbg; > > - /* > - * Non-VHE: Disable and flush SPE data generation > - * VHE: The vcpu can run, but it can't hide. > - */ > - if (!has_vhe()) > - __debug_save_spe_nvhe(&vcpu->arch.host_debug_state.pmscr_el1); > - > if (!(vcpu->arch.flags & KVM_ARM64_DEBUG_DIRTY)) > return; > > @@ -175,7 +168,7 @@ void __hyp_text __debug_switch_to_guest(struct kvm_vcpu *vcpu) > __debug_restore_state(vcpu, guest_dbg, guest_ctxt); > } > > -void __hyp_text __debug_switch_to_host(struct kvm_vcpu *vcpu) > +void __hyp_text __debug_restore_host_context(struct kvm_vcpu *vcpu) In the current state of the sources, __debug_switch_to_host() seems to save the guest debug state before restoring the host's: __debug_save_state(vcpu, guest_dbg, guest_ctxt); Since you're splitting the switch_to into save/restore operations, it feels like this would fit better __debug_save_guest_context() (currently empty) rather than __debug_restore_host_context(). Cheers,
diff --git a/arch/arm64/include/asm/kvm_hyp.h b/arch/arm64/include/asm/kvm_hyp.h index 782955db61dd..1c5ed80fcbda 100644 --- a/arch/arm64/include/asm/kvm_hyp.h +++ b/arch/arm64/include/asm/kvm_hyp.h @@ -164,8 +164,10 @@ void sysreg_restore_guest_state_vhe(struct kvm_cpu_context *ctxt); void __sysreg32_save_state(struct kvm_vcpu *vcpu); void __sysreg32_restore_state(struct kvm_vcpu *vcpu); -void __debug_switch_to_guest(struct kvm_vcpu *vcpu); -void __debug_switch_to_host(struct kvm_vcpu *vcpu); +void __debug_save_host_context(struct kvm_vcpu *vcpu); +void __debug_restore_guest_context(struct kvm_vcpu *vcpu); +void __debug_save_guest_context(struct kvm_vcpu *vcpu); +void __debug_restore_host_context(struct kvm_vcpu *vcpu); void __fpsimd_save_state(struct user_fpsimd_state *fp_regs); void __fpsimd_restore_state(struct user_fpsimd_state *fp_regs); diff --git a/arch/arm64/kvm/hyp/debug-sr.c b/arch/arm64/kvm/hyp/debug-sr.c index fa51236ebcb3..618884df1dc4 100644 --- a/arch/arm64/kvm/hyp/debug-sr.c +++ b/arch/arm64/kvm/hyp/debug-sr.c @@ -149,20 +149,13 @@ static void __hyp_text __debug_restore_state(struct kvm_vcpu *vcpu, write_sysreg(ctxt->sys_regs[MDCCINT_EL1], mdccint_el1); } -void __hyp_text __debug_switch_to_guest(struct kvm_vcpu *vcpu) +void __hyp_text __debug_restore_guest_context(struct kvm_vcpu *vcpu) { struct kvm_cpu_context *host_ctxt; struct kvm_cpu_context *guest_ctxt; struct kvm_guest_debug_arch *host_dbg; struct kvm_guest_debug_arch *guest_dbg; - /* - * Non-VHE: Disable and flush SPE data generation - * VHE: The vcpu can run, but it can't hide. - */ - if (!has_vhe()) - __debug_save_spe_nvhe(&vcpu->arch.host_debug_state.pmscr_el1); - if (!(vcpu->arch.flags & KVM_ARM64_DEBUG_DIRTY)) return; @@ -175,7 +168,7 @@ void __hyp_text __debug_switch_to_guest(struct kvm_vcpu *vcpu) __debug_restore_state(vcpu, guest_dbg, guest_ctxt); } -void __hyp_text __debug_switch_to_host(struct kvm_vcpu *vcpu) +void __hyp_text __debug_restore_host_context(struct kvm_vcpu *vcpu) { struct kvm_cpu_context *host_ctxt; struct kvm_cpu_context *guest_ctxt; @@ -199,6 +192,20 @@ void __hyp_text __debug_switch_to_host(struct kvm_vcpu *vcpu) vcpu->arch.flags &= ~KVM_ARM64_DEBUG_DIRTY; } +void __hyp_text __debug_save_host_context(struct kvm_vcpu *vcpu) +{ + /* + * Non-VHE: Disable and flush SPE data generation + * VHE: The vcpu can run, but it can't hide. + */ + if (!has_vhe()) + __debug_save_spe_nvhe(&vcpu->arch.host_debug_state.pmscr_el1); +} + +void __hyp_text __debug_save_guest_context(struct kvm_vcpu *vcpu) +{ +} + u32 __hyp_text __kvm_get_mdcr_el2(void) { return read_sysreg(mdcr_el2); diff --git a/arch/arm64/kvm/hyp/switch.c b/arch/arm64/kvm/hyp/switch.c index 9b2461138ddc..844f0dd7a7f0 100644 --- a/arch/arm64/kvm/hyp/switch.c +++ b/arch/arm64/kvm/hyp/switch.c @@ -515,6 +515,7 @@ int kvm_vcpu_run_vhe(struct kvm_vcpu *vcpu) guest_ctxt = &vcpu->arch.ctxt; sysreg_save_host_state_vhe(host_ctxt); + __debug_save_host_context(vcpu); /* * ARM erratum 1165522 requires us to configure both stage 1 and @@ -531,7 +532,7 @@ int kvm_vcpu_run_vhe(struct kvm_vcpu *vcpu) __activate_traps(vcpu); sysreg_restore_guest_state_vhe(guest_ctxt); - __debug_switch_to_guest(vcpu); + __debug_restore_guest_context(vcpu); __set_guest_arch_workaround_state(vcpu); @@ -545,6 +546,7 @@ int kvm_vcpu_run_vhe(struct kvm_vcpu *vcpu) __set_host_arch_workaround_state(vcpu); sysreg_save_guest_state_vhe(guest_ctxt); + __debug_save_guest_context(vcpu); __deactivate_traps(vcpu); @@ -553,7 +555,7 @@ int kvm_vcpu_run_vhe(struct kvm_vcpu *vcpu) if (vcpu->arch.flags & KVM_ARM64_FP_ENABLED) __fpsimd_save_fpexc32(vcpu); - __debug_switch_to_host(vcpu); + __debug_restore_host_context(vcpu); return exit_code; } @@ -587,6 +589,7 @@ int __hyp_text __kvm_vcpu_run_nvhe(struct kvm_vcpu *vcpu) pmu_switch_needed = __pmu_switch_to_guest(host_ctxt); __sysreg_save_state_nvhe(host_ctxt); + __debug_save_host_context(vcpu); __activate_vm(kern_hyp_va(vcpu->kvm)); __activate_traps(vcpu); @@ -600,7 +603,7 @@ int __hyp_text __kvm_vcpu_run_nvhe(struct kvm_vcpu *vcpu) */ __sysreg32_restore_state(vcpu); __sysreg_restore_state_nvhe(guest_ctxt); - __debug_switch_to_guest(vcpu); + __debug_restore_guest_context(vcpu); __set_guest_arch_workaround_state(vcpu); @@ -614,6 +617,7 @@ int __hyp_text __kvm_vcpu_run_nvhe(struct kvm_vcpu *vcpu) __set_host_arch_workaround_state(vcpu); __sysreg_save_state_nvhe(guest_ctxt); + __debug_save_guest_context(vcpu); __sysreg32_save_state(vcpu); __timer_disable_traps(vcpu); __hyp_vgic_save_state(vcpu); @@ -630,7 +634,7 @@ int __hyp_text __kvm_vcpu_run_nvhe(struct kvm_vcpu *vcpu) * This must come after restoring the host sysregs, since a non-VHE * system may enable SPE here and make use of the TTBRs. */ - __debug_switch_to_host(vcpu); + __debug_restore_host_context(vcpu); if (pmu_switch_needed) __pmu_switch_to_host(host_ctxt);
If we enable profiling buffer controls at EL1 generate a trap exception to EL2, it also changes profiling buffer to use EL1&0 stage 1 translation regime in case of VHE. To support SPE both in the guest and host, we need to first stop profiling and flush the profiling buffers before we activate/switch vm or enable/disable the traps. In prepartion to do that, lets split the debug save restore functionality into 4 steps: 1. debug_save_host_context - saves the host context 2. debug_restore_guest_context - restore the guest context 3. debug_save_guest_context - saves the guest context 4. debug_restore_host_context - restores the host context Lets rename existing __debug_switch_to_{host,guest} to make sure it's aligned to the above and just add the place holders for new ones getting added here as we need them to support SPE in guests. Signed-off-by: Sudeep Holla <sudeep.holla@arm.com> --- arch/arm64/include/asm/kvm_hyp.h | 6 ++++-- arch/arm64/kvm/hyp/debug-sr.c | 25 ++++++++++++++++--------- arch/arm64/kvm/hyp/switch.c | 12 ++++++++---- 3 files changed, 28 insertions(+), 15 deletions(-)