[PATCH v3 2/6] arm64: KVM: Move SPE and trace registers to the sysreg array

James Clark
2023-10-19T16:56:19Z

pmscr_el1 and trfcr_el1 are currently special cased in the
host_debug_state struct, but they're just registers after all so give
them entries in the sysreg array and refer to them through the host
context.

Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: James Clark <james.clark@arm.com>
---
arch/arm64/include/asm/kvm_host.h | 6 ++--
arch/arm64/include/asm/kvm_hyp.h | 4 +--
arch/arm64/kvm/hyp/nvhe/debug-sr.c | 44 +++++++++++++++---------------
arch/arm64/kvm/hyp/nvhe/switch.c | 4 +--
4 files changed, 28 insertions(+), 30 deletions(-)

diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h
index 4a966c0d7373..7c82927ddaf2 100644
--- a/arch/arm64/include/asm/kvm_host.h
+++ b/arch/arm64/include/asm/kvm_host.h
@@ -437,6 +437,8 @@ enum vcpu_sysreg {
CNTHP_CVAL_EL2,
CNTHV_CTL_EL2,
CNTHV_CVAL_EL2,
+ PMSCR_EL1, /* Statistical profiling extension */
+ TRFCR_EL1, /* Self-hosted trace filters */

NR_SYS_REGS /* Nothing after this line! */
};
@@ -570,10 +572,6 @@ struct kvm_vcpu_arch {
struct {
/* {Break,watch}point registers */
struct kvm_guest_debug_arch regs;
- /* Statistical profiling extension */
- u64 pmscr_el1;
- /* Self-hosted trace */
- u64 trfcr_el1;
} host_debug_state;

/* VGIC state */
diff --git a/arch/arm64/include/asm/kvm_hyp.h b/arch/arm64/include/asm/kvm_hyp.h
index 66efd67ea7e8..52ac90d419e7 100644
--- a/arch/arm64/include/asm/kvm_hyp.h
+++ b/arch/arm64/include/asm/kvm_hyp.h
@@ -103,8 +103,8 @@ void __debug_switch_to_guest(struct kvm_vcpu *vcpu);
void __debug_switch_to_host(struct kvm_vcpu *vcpu);

#ifdef __KVM_NVHE_HYPERVISOR__
-void __debug_save_host_buffers_nvhe(struct kvm_vcpu *vcpu);
-void __debug_restore_host_buffers_nvhe(struct kvm_vcpu *vcpu);
+void __debug_save_host_buffers_nvhe(struct kvm_cpu_context *host_ctxt);
+void __debug_restore_host_buffers_nvhe(struct kvm_cpu_context *host_ctxt);
#endif

void __fpsimd_save_state(struct user_fpsimd_state *fp_regs);
diff --git a/arch/arm64/kvm/hyp/nvhe/debug-sr.c b/arch/arm64/kvm/hyp/nvhe/debug-sr.c
index 4558c02eb352..f389ee59788c 100644
--- a/arch/arm64/kvm/hyp/nvhe/debug-sr.c
+++ b/arch/arm64/kvm/hyp/nvhe/debug-sr.c
@@ -14,12 +14,12 @@
#include <asm/kvm_hyp.h>
#include <asm/kvm_mmu.h>

-static void __debug_save_spe(u64 *pmscr_el1)
+static void __debug_save_spe(struct kvm_cpu_context *host_ctxt)
{
u64 reg;

/* Clear pmscr in case of early return */
- *pmscr_el1 = 0;
+ ctxt_sys_reg(host_ctxt, PMSCR_EL1) = 0;

/*
* At this point, we know that this CPU implements
@@ -31,7 +31,7 @@ static void __debug_save_spe(u64 *pmscr_el1)
return;

/* Yes; save the control register and disable data generation */
- *pmscr_el1 = read_sysreg_s(SYS_PMSCR_EL1);
+ ctxt_sys_reg(host_ctxt, PMSCR_EL1) = read_sysreg_s(SYS_PMSCR_EL1);
write_sysreg_s(0, SYS_PMSCR_EL1);
isb();

@@ -39,21 +39,21 @@ static void __debug_save_spe(u64 *pmscr_el1)
psb_csync();
}

-static void __debug_restore_spe(u64 pmscr_el1)
+static void __debug_restore_spe(struct kvm_cpu_context *host_ctxt)
{
- if (!pmscr_el1)
+ if (!ctxt_sys_reg(host_ctxt, PMSCR_EL1))
return;

/* The host page table is installed, but not yet synchronised */
isb();

/* Re-enable data generation */
- write_sysreg_s(pmscr_el1, SYS_PMSCR_EL1);
+ write_sysreg_s(ctxt_sys_reg(host_ctxt, PMSCR_EL1), SYS_PMSCR_EL1);
}

-static void __debug_save_trace(u64 *trfcr_el1)
+static void __debug_save_trace(struct kvm_cpu_context *host_ctxt)
{
- *trfcr_el1 = 0;
+ ctxt_sys_reg(host_ctxt, TRFCR_EL1) = 0;

/* Check if the TRBE is enabled */
if (!(read_sysreg_s(SYS_TRBLIMITR_EL1) & TRBLIMITR_EL1_E))
@@ -63,30 +63,30 @@ static void __debug_save_trace(u64 *trfcr_el1)
* Since access to TRFCR_EL1 is trapped, the guest can't
* modify the filtering set by the host.
*/
- *trfcr_el1 = read_sysreg_s(SYS_TRFCR_EL1);
+ ctxt_sys_reg(host_ctxt, TRFCR_EL1) = read_sysreg_s(SYS_TRFCR_EL1);
write_sysreg_s(0, SYS_TRFCR_EL1);
isb();
/* Drain the trace buffer to memory */
tsb_csync();
}

-static void __debug_restore_trace(u64 trfcr_el1)
+static void __debug_restore_trace(struct kvm_cpu_context *host_ctxt)
{
- if (!trfcr_el1)
+ if (!ctxt_sys_reg(host_ctxt, TRFCR_EL1))
return;

/* Restore trace filter controls */
- write_sysreg_s(trfcr_el1, SYS_TRFCR_EL1);
+ write_sysreg_s(ctxt_sys_reg(host_ctxt, TRFCR_EL1), SYS_TRFCR_EL1);
}

-void __debug_save_host_buffers_nvhe(struct kvm_vcpu *vcpu)
+void __debug_save_host_buffers_nvhe(struct kvm_cpu_context *host_ctxt)
{
/* Disable and flush SPE data generation */
- if (vcpu_get_flag(vcpu, DEBUG_STATE_SAVE_SPE))
- __debug_save_spe(&vcpu->arch.host_debug_state.pmscr_el1);
+ if (vcpu_get_flag(host_ctxt->__hyp_running_vcpu, DEBUG_STATE_SAVE_SPE))
+ __debug_save_spe(host_ctxt);
/* Disable and flush Self-Hosted Trace generation */
- if (vcpu_get_flag(vcpu, DEBUG_STATE_SAVE_TRBE))
- __debug_save_trace(&vcpu->arch.host_debug_state.trfcr_el1);
+ if (vcpu_get_flag(host_ctxt->__hyp_running_vcpu, DEBUG_STATE_SAVE_TRBE))
+ __debug_save_trace(host_ctxt);
}

void __debug_switch_to_guest(struct kvm_vcpu *vcpu)
@@ -94,12 +94,12 @@ void __debug_switch_to_guest(struct kvm_vcpu *vcpu)
__debug_switch_to_guest_common(vcpu);
}

-void __debug_restore_host_buffers_nvhe(struct kvm_vcpu *vcpu)
+void __debug_restore_host_buffers_nvhe(struct kvm_cpu_context *host_ctxt)
{
- if (vcpu_get_flag(vcpu, DEBUG_STATE_SAVE_SPE))
- __debug_restore_spe(vcpu->arch.host_debug_state.pmscr_el1);
- if (vcpu_get_flag(vcpu, DEBUG_STATE_SAVE_TRBE))
- __debug_restore_trace(vcpu->arch.host_debug_state.trfcr_el1);
+ if (vcpu_get_flag(host_ctxt->__hyp_running_vcpu, DEBUG_STATE_SAVE_SPE))
+ __debug_restore_spe(host_ctxt);
+ if (vcpu_get_flag(host_ctxt->__hyp_running_vcpu, DEBUG_STATE_SAVE_TRBE))
+ __debug_restore_trace(host_ctxt);
}

void __debug_switch_to_host(struct kvm_vcpu *vcpu)
diff --git a/arch/arm64/kvm/hyp/nvhe/switch.c b/arch/arm64/kvm/hyp/nvhe/switch.c
index c50f8459e4fc..6b4b24ae077f 100644
--- a/arch/arm64/kvm/hyp/nvhe/switch.c
+++ b/arch/arm64/kvm/hyp/nvhe/switch.c
@@ -278,7 +278,7 @@ int __kvm_vcpu_run(struct kvm_vcpu *vcpu)
* translation regime to EL2 (via MDCR_EL2_E2PB == 0) and
* before we load guest Stage1.
*/
- __debug_save_host_buffers_nvhe(vcpu);
+ __debug_save_host_buffers_nvhe(host_ctxt);

/*
* We're about to restore some new MMU state. Make sure
@@ -345,7 +345,7 @@ int __kvm_vcpu_run(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_restore_host_buffers_nvhe(vcpu);
+ __debug_restore_host_buffers_nvhe(host_ctxt);

if (pmu_switch_needed)
__pmu_switch_to_host(vcpu);
--
2.34.1