[PATCH v2 06/18] arm64: KVM: split debug save restore across vm/traps activation
From: Andrew Murray <hidden>
Date: 2019-12-20 14:31:05
Also in:
kvm, kvmarm, lkml
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: Sudeep Holla <redacted>
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 <redacted>
Signed-off-by: Andrew Murray <redacted>
---
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 97f21cc66657..011e7963f772 100644
--- a/arch/arm64/include/asm/kvm_hyp.h
+++ b/arch/arm64/include/asm/kvm_hyp.h@@ -69,8 +69,10 @@ 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 98be2f11c16c..c803daebd596 100644
--- a/arch/arm64/kvm/hyp/debug-sr.c
+++ b/arch/arm64/kvm/hyp/debug-sr.c@@ -168,20 +168,13 @@ 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;
@@ -194,7 +187,7 @@ 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;
@@ -218,6 +211,20 @@ 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 250f13910882..67b7c160f65b 100644
--- a/arch/arm64/kvm/hyp/switch.c
+++ b/arch/arm64/kvm/hyp/switch.c@@ -626,6 +626,7 @@ 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
@@ -642,7 +643,7 @@ 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);
@@ -656,6 +657,7 @@ 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);
@@ -664,7 +666,7 @@ 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; }
@@ -698,6 +700,7 @@ 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); /* * We must restore the 32-bit state before the sysregs, thanks
@@ -716,7 +719,7 @@ int __hyp_text __kvm_vcpu_run_nvhe(struct kvm_vcpu *vcpu) __hyp_vgic_restore_state(vcpu); __timer_enable_traps(vcpu); - __debug_switch_to_guest(vcpu); + __debug_restore_guest_context(vcpu); __set_guest_arch_workaround_state(vcpu);
@@ -730,6 +733,7 @@ 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);
@@ -746,7 +750,7 @@ 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);
--
2.21.0
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