[PATCH v2 09/15] arm64: KVM: add support to save/restore SPE profiling buffer controls
From: Sudeep Holla <hidden>
Date: 2019-05-23 10:36:21
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
Currently since we don't support profiling using SPE in the guests, we just save the PMSCR_EL1, flush the profiling buffers and disable sampling. However in order to support simultaneous sampling both in the host and guests, we need to save and reatore the complete SPE profiling buffer controls' context. Let's add the support for the same and keep it disabled for now. We can enable it conditionally only if guests are allowed to use SPE. Signed-off-by: Sudeep Holla <redacted> --- arch/arm64/kvm/hyp/debug-sr.c | 44 ++++++++++++++++++++++++++++------- 1 file changed, 35 insertions(+), 9 deletions(-)
diff --git a/arch/arm64/kvm/hyp/debug-sr.c b/arch/arm64/kvm/hyp/debug-sr.c
index a2714a5eb3e9..a4e6eaf5934f 100644
--- a/arch/arm64/kvm/hyp/debug-sr.c
+++ b/arch/arm64/kvm/hyp/debug-sr.c@@ -66,7 +66,8 @@ default: write_debug(ptr[0], reg, 0); \ } -static void __hyp_text __debug_save_spe_nvhe(struct kvm_cpu_context *ctxt) +static void __hyp_text +__debug_save_spe_nvhe(struct kvm_cpu_context *ctxt, bool full_ctxt) { u64 reg;
@@ -83,22 +84,37 @@ static void __hyp_text __debug_save_spe_nvhe(struct kvm_cpu_context *ctxt) if (reg & BIT(SYS_PMBIDR_EL1_P_SHIFT)) return; - /* No; is the host actually using the thing? */ - reg = read_sysreg_s(SYS_PMBLIMITR_EL1); - if (!(reg & BIT(SYS_PMBLIMITR_EL1_E_SHIFT))) + /* Save the control register and disable data generation */ + ctxt->sys_regs[PMSCR_EL1] = read_sysreg_el1_s(SYS_PMSCR); + + if (!ctxt->sys_regs[PMSCR_EL1]) return; - /* Yes; save the control register and disable data generation */ - ctxt->sys_regs[PMSCR_EL1] = read_sysreg_el1_s(SYS_PMSCR); write_sysreg_el1_s(0, SYS_PMSCR); isb(); /* Now drain all buffered data to memory */ psb_csync(); dsb(nsh); + + if (!full_ctxt) + return; + + ctxt->sys_regs[PMBLIMITR_EL1] = read_sysreg_s(SYS_PMBLIMITR_EL1); + write_sysreg_s(0, SYS_PMBLIMITR_EL1); + isb(); + + ctxt->sys_regs[PMSICR_EL1] = read_sysreg_s(SYS_PMSICR_EL1); + ctxt->sys_regs[PMSIRR_EL1] = read_sysreg_s(SYS_PMSIRR_EL1); + ctxt->sys_regs[PMSFCR_EL1] = read_sysreg_s(SYS_PMSFCR_EL1); + ctxt->sys_regs[PMSEVFR_EL1] = read_sysreg_s(SYS_PMSEVFR_EL1); + ctxt->sys_regs[PMSLATFR_EL1] = read_sysreg_s(SYS_PMSLATFR_EL1); + ctxt->sys_regs[PMBPTR_EL1] = read_sysreg_s(SYS_PMBPTR_EL1); + ctxt->sys_regs[PMBSR_EL1] = read_sysreg_s(SYS_PMBSR_EL1); } -static void __hyp_text __debug_restore_spe_nvhe(struct kvm_cpu_context *ctxt) +static void __hyp_text +__debug_restore_spe_nvhe(struct kvm_cpu_context *ctxt, bool full_ctxt) { if (!ctxt->sys_regs[PMSCR_EL1]) return;
@@ -107,6 +123,16 @@ static void __hyp_text __debug_restore_spe_nvhe(struct kvm_cpu_context *ctxt) isb(); /* Re-enable data generation */ + if (full_ctxt) { + write_sysreg_s(ctxt->sys_regs[PMBPTR_EL1], SYS_PMBPTR_EL1); + write_sysreg_s(ctxt->sys_regs[PMBLIMITR_EL1], SYS_PMBLIMITR_EL1); + write_sysreg_s(ctxt->sys_regs[PMSFCR_EL1], SYS_PMSFCR_EL1); + write_sysreg_s(ctxt->sys_regs[PMSEVFR_EL1], SYS_PMSEVFR_EL1); + write_sysreg_s(ctxt->sys_regs[PMSLATFR_EL1], SYS_PMSLATFR_EL1); + write_sysreg_s(ctxt->sys_regs[PMSIRR_EL1], SYS_PMSIRR_EL1); + write_sysreg_s(ctxt->sys_regs[PMSICR_EL1], SYS_PMSICR_EL1); + write_sysreg_s(ctxt->sys_regs[PMBSR_EL1], SYS_PMBSR_EL1); + } write_sysreg_el1_s(ctxt->sys_regs[PMSCR_EL1], SYS_PMSCR); }
@@ -179,7 +205,7 @@ void __hyp_text __debug_restore_host_context(struct kvm_vcpu *vcpu) guest_ctxt = &vcpu->arch.ctxt; if (!has_vhe()) - __debug_restore_spe_nvhe(host_ctxt); + __debug_restore_spe_nvhe(host_ctxt, false); if (!(vcpu->arch.flags & KVM_ARM64_DEBUG_DIRTY)) return;
@@ -203,7 +229,7 @@ void __hyp_text __debug_save_host_context(struct kvm_vcpu *vcpu) host_ctxt = kern_hyp_va(vcpu->arch.host_cpu_context); if (!has_vhe()) - __debug_save_spe_nvhe(host_ctxt); + __debug_save_spe_nvhe(host_ctxt, false); } void __hyp_text __debug_save_guest_context(struct kvm_vcpu *vcpu)
--
2.17.1
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