diff options
Diffstat (limited to 'arch')
| -rw-r--r-- | arch/arm64/include/asm/kvm_host.h | 2 | ||||
| -rw-r--r-- | arch/arm64/kvm/hyp/nvhe/debug-sr.c | 116 | ||||
| -rw-r--r-- | arch/arm64/kvm/hyp/nvhe/switch.c | 2 |
3 files changed, 95 insertions, 25 deletions
diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h index 8545811e2238..f8c1e6920fd3 100644 --- a/arch/arm64/include/asm/kvm_host.h +++ b/arch/arm64/include/asm/kvm_host.h @@ -790,8 +790,10 @@ struct kvm_host_data { struct kvm_guest_debug_arch regs; /* Statistical profiling extension */ u64 pmscr_el1; + u64 pmblimitr_el1; /* Self-hosted trace */ u64 trfcr_el1; + u64 trblimitr_el1; /* Values of trap registers for the host before guest entry. */ u64 mdcr_el2; u64 brbcr_el1; diff --git a/arch/arm64/kvm/hyp/nvhe/debug-sr.c b/arch/arm64/kvm/hyp/nvhe/debug-sr.c index 2a1c0f49792b..f8904391c125 100644 --- a/arch/arm64/kvm/hyp/nvhe/debug-sr.c +++ b/arch/arm64/kvm/hyp/nvhe/debug-sr.c @@ -14,20 +14,20 @@ #include <asm/kvm_hyp.h> #include <asm/kvm_mmu.h> -static void __debug_save_spe(u64 *pmscr_el1) +static void __debug_save_spe(void) { - u64 reg; + u64 *pmscr_el1, *pmblimitr_el1; - /* Clear pmscr in case of early return */ - *pmscr_el1 = 0; + pmscr_el1 = host_data_ptr(host_debug_state.pmscr_el1); + pmblimitr_el1 = host_data_ptr(host_debug_state.pmblimitr_el1); /* * At this point, we know that this CPU implements * SPE and is available to the host. * Check if the host is actually using it ? */ - reg = read_sysreg_s(SYS_PMBLIMITR_EL1); - if (!(reg & BIT(PMBLIMITR_EL1_E_SHIFT))) + *pmblimitr_el1 = read_sysreg_s(SYS_PMBLIMITR_EL1); + if (!(*pmblimitr_el1 & BIT(PMBLIMITR_EL1_E_SHIFT))) return; /* Yes; save the control register and disable data generation */ @@ -37,18 +37,29 @@ static void __debug_save_spe(u64 *pmscr_el1) /* Now drain all buffered data to memory */ psb_csync(); + dsb(nsh); + + /* And disable the profiling buffer */ + write_sysreg_s(0, SYS_PMBLIMITR_EL1); + isb(); } -static void __debug_restore_spe(u64 pmscr_el1) +static void __debug_restore_spe(void) { - if (!pmscr_el1) + u64 pmblimitr_el1 = *host_data_ptr(host_debug_state.pmblimitr_el1); + + if (!(pmblimitr_el1 & BIT(PMBLIMITR_EL1_E_SHIFT))) return; /* The host page table is installed, but not yet synchronised */ isb(); + /* Re-enable the profiling buffer. */ + write_sysreg_s(pmblimitr_el1, SYS_PMBLIMITR_EL1); + isb(); + /* Re-enable data generation */ - write_sysreg_el1(pmscr_el1, SYS_PMSCR); + write_sysreg_el1(*host_data_ptr(host_debug_state.pmscr_el1), SYS_PMSCR); } static void __trace_do_switch(u64 *saved_trfcr, u64 new_trfcr) @@ -57,12 +68,54 @@ static void __trace_do_switch(u64 *saved_trfcr, u64 new_trfcr) write_sysreg_el1(new_trfcr, SYS_TRFCR); } -static bool __trace_needs_drain(void) +static void __trace_drain_and_disable(void) { - if (is_protected_kvm_enabled() && host_data_test_flag(HAS_TRBE)) - return read_sysreg_s(SYS_TRBLIMITR_EL1) & TRBLIMITR_EL1_E; + u64 *trblimitr_el1 = host_data_ptr(host_debug_state.trblimitr_el1); + bool needs_drain = is_protected_kvm_enabled() ? + host_data_test_flag(HAS_TRBE) : + host_data_test_flag(TRBE_ENABLED); + + if (!needs_drain) { + *trblimitr_el1 = 0; + return; + } + + *trblimitr_el1 = read_sysreg_s(SYS_TRBLIMITR_EL1); + if (*trblimitr_el1 & TRBLIMITR_EL1_E) { + /* + * The host has enabled the Trace Buffer Unit so we have + * to beat the CPU with a stick until it stops accessing + * memory. + */ - return host_data_test_flag(TRBE_ENABLED); + /* First, ensure that our prior write to TRFCR has stuck. */ + isb(); + + /* Now synchronise with the trace and drain the buffer. */ + tsb_csync(); + dsb(nsh); + + /* + * With no more trace being generated, we can disable the + * Trace Buffer Unit. + */ + write_sysreg_s(0, SYS_TRBLIMITR_EL1); + if (cpus_have_final_cap(ARM64_WORKAROUND_2064142)) { + /* + * Some CPUs are so good, we have to drain 'em + * twice. + */ + tsb_csync(); + dsb(nsh); + } + + /* + * Ensure that the Trace Buffer Unit is disabled before + * we start mucking with the stage-2 and trap + * configuration. + */ + isb(); + } } static bool __trace_needs_switch(void) @@ -79,21 +132,34 @@ static void __trace_switch_to_guest(void) __trace_do_switch(host_data_ptr(host_debug_state.trfcr_el1), *host_data_ptr(trfcr_while_in_guest)); - - if (__trace_needs_drain()) { - isb(); - tsb_csync(); - } + __trace_drain_and_disable(); } static void __trace_switch_to_host(void) { + u64 trblimitr_el1 = *host_data_ptr(host_debug_state.trblimitr_el1); + + if (trblimitr_el1 & TRBLIMITR_EL1_E) { + /* Re-enable the Trace Buffer Unit for the host. */ + write_sysreg_s(trblimitr_el1, SYS_TRBLIMITR_EL1); + isb(); + if (cpus_have_final_cap(ARM64_WORKAROUND_2038923)) { + /* + * Make sure the unit is re-enabled before we + * poke TRFCR. + */ + isb(); + } + } + __trace_do_switch(host_data_ptr(trfcr_while_in_guest), *host_data_ptr(host_debug_state.trfcr_el1)); } -static void __debug_save_brbe(u64 *brbcr_el1) +static void __debug_save_brbe(void) { + u64 *brbcr_el1 = host_data_ptr(host_debug_state.brbcr_el1); + *brbcr_el1 = 0; /* Check if the BRBE is enabled */ @@ -109,8 +175,10 @@ static void __debug_save_brbe(u64 *brbcr_el1) write_sysreg_el1(0, SYS_BRBCR); } -static void __debug_restore_brbe(u64 brbcr_el1) +static void __debug_restore_brbe(void) { + u64 brbcr_el1 = *host_data_ptr(host_debug_state.brbcr_el1); + if (!brbcr_el1) return; @@ -122,11 +190,11 @@ void __debug_save_host_buffers_nvhe(struct kvm_vcpu *vcpu) { /* Disable and flush SPE data generation */ if (host_data_test_flag(HAS_SPE)) - __debug_save_spe(host_data_ptr(host_debug_state.pmscr_el1)); + __debug_save_spe(); /* Disable BRBE branch records */ if (host_data_test_flag(HAS_BRBE)) - __debug_save_brbe(host_data_ptr(host_debug_state.brbcr_el1)); + __debug_save_brbe(); if (__trace_needs_switch()) __trace_switch_to_guest(); @@ -140,9 +208,9 @@ void __debug_switch_to_guest(struct kvm_vcpu *vcpu) void __debug_restore_host_buffers_nvhe(struct kvm_vcpu *vcpu) { if (host_data_test_flag(HAS_SPE)) - __debug_restore_spe(*host_data_ptr(host_debug_state.pmscr_el1)); + __debug_restore_spe(); if (host_data_test_flag(HAS_BRBE)) - __debug_restore_brbe(*host_data_ptr(host_debug_state.brbcr_el1)); + __debug_restore_brbe(); if (__trace_needs_switch()) __trace_switch_to_host(); } diff --git a/arch/arm64/kvm/hyp/nvhe/switch.c b/arch/arm64/kvm/hyp/nvhe/switch.c index ed8830c707b0..923351f70ff8 100644 --- a/arch/arm64/kvm/hyp/nvhe/switch.c +++ b/arch/arm64/kvm/hyp/nvhe/switch.c @@ -293,7 +293,7 @@ int __kvm_vcpu_run(struct kvm_vcpu *vcpu) * We're about to restore some new MMU state. Make sure * ongoing page-table walks that have started before we * trapped to EL2 have completed. This also synchronises the - * above disabling of BRBE, SPE and TRBE. + * above disabling of BRBE. * * See DDI0487I.a D8.1.5 "Out-of-context translation regimes", * rule R_LFHQG and subsequent information statements. |