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[PATCH v9 28/30] KVM: arm64: Add hyp_enter/hyp_exit events to nVHE/pKVM hyp

Vincent Donnefort posted 30 patches 2 months, 1 week ago
There is a newer version of this series
[PATCH v9 28/30] KVM: arm64: Add hyp_enter/hyp_exit events to nVHE/pKVM hyp
Posted by Vincent Donnefort 2 months, 1 week ago 
The hyp_enter and hyp_exit events are logged by the hypervisor any time
it is entered and exited.

Signed-off-by: Vincent Donnefort <vdonnefort@google.com>

diff --git a/arch/arm64/include/asm/kvm_hypevents.h b/arch/arm64/include/asm/kvm_hypevents.h
index d6e033c96c52..268b3cd7a1b2 100644
--- a/arch/arm64/include/asm/kvm_hypevents.h
+++ b/arch/arm64/include/asm/kvm_hypevents.h
@@ -7,4 +7,39 @@
 #include <nvhe/trace.h>
 #endif
 
+#ifndef __HYP_ENTER_EXIT_REASON
+#define __HYP_ENTER_EXIT_REASON
+enum hyp_enter_exit_reason {
+	HYP_REASON_SMC,
+	HYP_REASON_HVC,
+	HYP_REASON_PSCI,
+	HYP_REASON_HOST_ABORT,
+	HYP_REASON_GUEST_EXIT,
+	HYP_REASON_ERET_HOST,
+	HYP_REASON_ERET_GUEST,
+	HYP_REASON_UNKNOWN	/* Must be last */
+};
+#endif
+
+HYP_EVENT(hyp_enter,
+	HE_PROTO(u8 reason),
+	HE_STRUCT(
+		he_field(u8, reason)
+	),
+	HE_ASSIGN(
+		__entry->reason = reason;
+	),
+	HE_PRINTK("reason=%s", __hyp_enter_exit_reason_str(__entry->reason))
+);
+
+HYP_EVENT(hyp_exit,
+	HE_PROTO(u8 reason),
+	HE_STRUCT(
+		he_field(u8, reason)
+	),
+	HE_ASSIGN(
+		__entry->reason = reason;
+	),
+	HE_PRINTK("reason=%s", __hyp_enter_exit_reason_str(__entry->reason))
+);
 #endif
diff --git a/arch/arm64/kvm/hyp/include/nvhe/arm-smccc.h b/arch/arm64/kvm/hyp/include/nvhe/arm-smccc.h
new file mode 100644
index 000000000000..7cd0f701f3c9
--- /dev/null
+++ b/arch/arm64/kvm/hyp/include/nvhe/arm-smccc.h
@@ -0,0 +1,23 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+#ifndef __ARM64_KVM_HYP_NVHE_ARM_SMCCC_H__
+#define __ARM64_KVM_HYP_NVHE_ARM_SMCCC_H__
+
+#include <asm/kvm_hypevents.h>
+
+#include <linux/arm-smccc.h>
+
+#define hyp_smccc_1_1_smc(...)					\
+	do {							\
+		trace_hyp_exit(HYP_REASON_SMC);			\
+		arm_smccc_1_1_smc(__VA_ARGS__);			\
+		trace_hyp_enter(HYP_REASON_SMC);		\
+	} while (0)
+
+#define hyp_smccc_1_2_smc(...)					\
+	do {							\
+		trace_hyp_exit(HYP_REASON_SMC);			\
+		arm_smccc_1_2_smc(__VA_ARGS__);			\
+		trace_hyp_enter(HYP_REASON_SMC);		\
+	} while (0)
+
+#endif /* __ARM64_KVM_HYP_NVHE_ARM_SMCCC_H__ */
diff --git a/arch/arm64/kvm/hyp/nvhe/ffa.c b/arch/arm64/kvm/hyp/nvhe/ffa.c
index 58b7d0c477d7..73d79f9de850 100644
--- a/arch/arm64/kvm/hyp/nvhe/ffa.c
+++ b/arch/arm64/kvm/hyp/nvhe/ffa.c
@@ -26,10 +26,10 @@
  * the duration and are therefore serialised.
  */
 
-#include <linux/arm-smccc.h>
 #include <linux/arm_ffa.h>
 #include <asm/kvm_pkvm.h>
 
+#include <nvhe/arm-smccc.h>
 #include <nvhe/ffa.h>
 #include <nvhe/mem_protect.h>
 #include <nvhe/memory.h>
@@ -147,7 +147,7 @@ static int ffa_map_hyp_buffers(u64 ffa_page_count)
 {
 	struct arm_smccc_1_2_regs res;
 
-	arm_smccc_1_2_smc(&(struct arm_smccc_1_2_regs) {
+	hyp_smccc_1_2_smc(&(struct arm_smccc_1_2_regs) {
 		.a0 = FFA_FN64_RXTX_MAP,
 		.a1 = hyp_virt_to_phys(hyp_buffers.tx),
 		.a2 = hyp_virt_to_phys(hyp_buffers.rx),
@@ -161,7 +161,7 @@ static int ffa_unmap_hyp_buffers(void)
 {
 	struct arm_smccc_1_2_regs res;
 
-	arm_smccc_1_2_smc(&(struct arm_smccc_1_2_regs) {
+	hyp_smccc_1_2_smc(&(struct arm_smccc_1_2_regs) {
 		.a0 = FFA_RXTX_UNMAP,
 		.a1 = HOST_FFA_ID,
 	}, &res);
@@ -172,7 +172,7 @@ static int ffa_unmap_hyp_buffers(void)
 static void ffa_mem_frag_tx(struct arm_smccc_1_2_regs *res, u32 handle_lo,
 			     u32 handle_hi, u32 fraglen, u32 endpoint_id)
 {
-	arm_smccc_1_2_smc(&(struct arm_smccc_1_2_regs) {
+	hyp_smccc_1_2_smc(&(struct arm_smccc_1_2_regs) {
 		.a0 = FFA_MEM_FRAG_TX,
 		.a1 = handle_lo,
 		.a2 = handle_hi,
@@ -184,7 +184,7 @@ static void ffa_mem_frag_tx(struct arm_smccc_1_2_regs *res, u32 handle_lo,
 static void ffa_mem_frag_rx(struct arm_smccc_1_2_regs *res, u32 handle_lo,
 			     u32 handle_hi, u32 fragoff)
 {
-	arm_smccc_1_2_smc(&(struct arm_smccc_1_2_regs) {
+	hyp_smccc_1_2_smc(&(struct arm_smccc_1_2_regs) {
 		.a0 = FFA_MEM_FRAG_RX,
 		.a1 = handle_lo,
 		.a2 = handle_hi,
@@ -196,7 +196,7 @@ static void ffa_mem_frag_rx(struct arm_smccc_1_2_regs *res, u32 handle_lo,
 static void ffa_mem_xfer(struct arm_smccc_1_2_regs *res, u64 func_id, u32 len,
 			  u32 fraglen)
 {
-	arm_smccc_1_2_smc(&(struct arm_smccc_1_2_regs) {
+	hyp_smccc_1_2_smc(&(struct arm_smccc_1_2_regs) {
 		.a0 = func_id,
 		.a1 = len,
 		.a2 = fraglen,
@@ -206,7 +206,7 @@ static void ffa_mem_xfer(struct arm_smccc_1_2_regs *res, u64 func_id, u32 len,
 static void ffa_mem_reclaim(struct arm_smccc_1_2_regs *res, u32 handle_lo,
 			     u32 handle_hi, u32 flags)
 {
-	arm_smccc_1_2_smc(&(struct arm_smccc_1_2_regs) {
+	hyp_smccc_1_2_smc(&(struct arm_smccc_1_2_regs) {
 		.a0 = FFA_MEM_RECLAIM,
 		.a1 = handle_lo,
 		.a2 = handle_hi,
@@ -216,7 +216,7 @@ static void ffa_mem_reclaim(struct arm_smccc_1_2_regs *res, u32 handle_lo,
 
 static void ffa_retrieve_req(struct arm_smccc_1_2_regs *res, u32 len)
 {
-	arm_smccc_1_2_smc(&(struct arm_smccc_1_2_regs) {
+	hyp_smccc_1_2_smc(&(struct arm_smccc_1_2_regs) {
 		.a0 = FFA_FN64_MEM_RETRIEVE_REQ,
 		.a1 = len,
 		.a2 = len,
@@ -225,7 +225,7 @@ static void ffa_retrieve_req(struct arm_smccc_1_2_regs *res, u32 len)
 
 static void ffa_rx_release(struct arm_smccc_1_2_regs *res)
 {
-	arm_smccc_1_2_smc(&(struct arm_smccc_1_2_regs) {
+	hyp_smccc_1_2_smc(&(struct arm_smccc_1_2_regs) {
 		.a0 = FFA_RX_RELEASE,
 	}, res);
 }
@@ -728,7 +728,7 @@ static int hyp_ffa_post_init(void)
 	size_t min_rxtx_sz;
 	struct arm_smccc_1_2_regs res;
 
-	arm_smccc_1_2_smc(&(struct arm_smccc_1_2_regs){
+	hyp_smccc_1_2_smc(&(struct arm_smccc_1_2_regs){
 		.a0 = FFA_ID_GET,
 	}, &res);
 	if (res.a0 != FFA_SUCCESS)
@@ -737,7 +737,7 @@ static int hyp_ffa_post_init(void)
 	if (res.a2 != HOST_FFA_ID)
 		return -EINVAL;
 
-	arm_smccc_1_2_smc(&(struct arm_smccc_1_2_regs){
+	hyp_smccc_1_2_smc(&(struct arm_smccc_1_2_regs){
 		.a0 = FFA_FEATURES,
 		.a1 = FFA_FN64_RXTX_MAP,
 	}, &res);
@@ -788,7 +788,7 @@ static void do_ffa_version(struct arm_smccc_1_2_regs *res,
 	 * first if TEE supports it.
 	 */
 	if (FFA_MINOR_VERSION(ffa_req_version) < FFA_MINOR_VERSION(hyp_ffa_version)) {
-		arm_smccc_1_2_smc(&(struct arm_smccc_1_2_regs) {
+		hyp_smccc_1_2_smc(&(struct arm_smccc_1_2_regs) {
 			.a0 = FFA_VERSION,
 			.a1 = ffa_req_version,
 		}, res);
@@ -824,7 +824,7 @@ static void do_ffa_part_get(struct arm_smccc_1_2_regs *res,
 		goto out_unlock;
 	}
 
-	arm_smccc_1_2_smc(&(struct arm_smccc_1_2_regs) {
+	hyp_smccc_1_2_smc(&(struct arm_smccc_1_2_regs) {
 		.a0 = FFA_PARTITION_INFO_GET,
 		.a1 = uuid0,
 		.a2 = uuid1,
@@ -939,7 +939,7 @@ int hyp_ffa_init(void *pages)
 	if (kvm_host_psci_config.smccc_version < ARM_SMCCC_VERSION_1_2)
 		return 0;
 
-	arm_smccc_1_2_smc(&(struct arm_smccc_1_2_regs) {
+	hyp_smccc_1_2_smc(&(struct arm_smccc_1_2_regs) {
 		.a0 = FFA_VERSION,
 		.a1 = FFA_VERSION_1_2,
 	}, &res);
diff --git a/arch/arm64/kvm/hyp/nvhe/hyp-main.c b/arch/arm64/kvm/hyp/nvhe/hyp-main.c
index 446603cdad7b..ffda4850022f 100644
--- a/arch/arm64/kvm/hyp/nvhe/hyp-main.c
+++ b/arch/arm64/kvm/hyp/nvhe/hyp-main.c
@@ -12,6 +12,7 @@
 #include <asm/kvm_emulate.h>
 #include <asm/kvm_host.h>
 #include <asm/kvm_hyp.h>
+#include <asm/kvm_hypevents.h>
 #include <asm/kvm_mmu.h>
 
 #include <nvhe/ffa.h>
@@ -728,7 +729,9 @@ static void handle_host_hcall(struct kvm_cpu_context *host_ctxt)
 
 static void default_host_smc_handler(struct kvm_cpu_context *host_ctxt)
 {
+	trace_hyp_exit(HYP_REASON_SMC);
 	__kvm_hyp_host_forward_smc(host_ctxt);
+	trace_hyp_enter(HYP_REASON_SMC);
 }
 
 static void handle_host_smc(struct kvm_cpu_context *host_ctxt)
@@ -752,18 +755,24 @@ void handle_trap(struct kvm_cpu_context *host_ctxt)
 {
 	u64 esr = read_sysreg_el2(SYS_ESR);
 
+
 	switch (ESR_ELx_EC(esr)) {
 	case ESR_ELx_EC_HVC64:
+		trace_hyp_enter(HYP_REASON_HVC);
 		handle_host_hcall(host_ctxt);
 		break;
 	case ESR_ELx_EC_SMC64:
+		trace_hyp_enter(HYP_REASON_SMC);
 		handle_host_smc(host_ctxt);
 		break;
 	case ESR_ELx_EC_IABT_LOW:
 	case ESR_ELx_EC_DABT_LOW:
+		trace_hyp_enter(HYP_REASON_HOST_ABORT);
 		handle_host_mem_abort(host_ctxt);
 		break;
 	default:
 		BUG();
 	}
+
+	trace_hyp_exit(HYP_REASON_ERET_HOST);
 }
diff --git a/arch/arm64/kvm/hyp/nvhe/psci-relay.c b/arch/arm64/kvm/hyp/nvhe/psci-relay.c
index c3e196fb8b18..58658e09c372 100644
--- a/arch/arm64/kvm/hyp/nvhe/psci-relay.c
+++ b/arch/arm64/kvm/hyp/nvhe/psci-relay.c
@@ -6,11 +6,12 @@
 
 #include <asm/kvm_asm.h>
 #include <asm/kvm_hyp.h>
+#include <asm/kvm_hypevents.h>
 #include <asm/kvm_mmu.h>
-#include <linux/arm-smccc.h>
 #include <linux/kvm_host.h>
 #include <uapi/linux/psci.h>
 
+#include <nvhe/arm-smccc.h>
 #include <nvhe/memory.h>
 #include <nvhe/trap_handler.h>
 
@@ -65,7 +66,7 @@ static unsigned long psci_call(unsigned long fn, unsigned long arg0,
 {
 	struct arm_smccc_res res;
 
-	arm_smccc_1_1_smc(fn, arg0, arg1, arg2, &res);
+	hyp_smccc_1_1_smc(fn, arg0, arg1, arg2, &res);
 	return res.a0;
 }
 
@@ -205,6 +206,7 @@ asmlinkage void __noreturn __kvm_host_psci_cpu_entry(bool is_cpu_on)
 	struct psci_boot_args *boot_args;
 	struct kvm_cpu_context *host_ctxt;
 
+	trace_hyp_enter(HYP_REASON_PSCI);
 	host_ctxt = host_data_ptr(host_ctxt);
 
 	if (is_cpu_on)
@@ -221,6 +223,7 @@ asmlinkage void __noreturn __kvm_host_psci_cpu_entry(bool is_cpu_on)
 	write_sysreg_el1(INIT_SCTLR_EL1_MMU_OFF, SYS_SCTLR);
 	write_sysreg(INIT_PSTATE_EL1, SPSR_EL2);
 
+	trace_hyp_exit(HYP_REASON_PSCI);
 	__host_enter(host_ctxt);
 }
 
diff --git a/arch/arm64/kvm/hyp/nvhe/switch.c b/arch/arm64/kvm/hyp/nvhe/switch.c
index d3b9ec8a7c28..3dc2bbab4bfc 100644
--- a/arch/arm64/kvm/hyp/nvhe/switch.c
+++ b/arch/arm64/kvm/hyp/nvhe/switch.c
@@ -7,7 +7,6 @@
 #include <hyp/switch.h>
 #include <hyp/sysreg-sr.h>
 
-#include <linux/arm-smccc.h>
 #include <linux/kvm_host.h>
 #include <linux/types.h>
 #include <linux/jump_label.h>
@@ -21,6 +20,7 @@
 #include <asm/kvm_asm.h>
 #include <asm/kvm_emulate.h>
 #include <asm/kvm_hyp.h>
+#include <asm/kvm_hypevents.h>
 #include <asm/kvm_mmu.h>
 #include <asm/fpsimd.h>
 #include <asm/debug-monitors.h>
@@ -308,10 +308,13 @@ int __kvm_vcpu_run(struct kvm_vcpu *vcpu)
 	__debug_switch_to_guest(vcpu);
 
 	do {
+		trace_hyp_exit(HYP_REASON_ERET_GUEST);
+
 		/* Jump in the fire! */
 		exit_code = __guest_enter(vcpu);
 
 		/* And we're baaack! */
+		trace_hyp_enter(HYP_REASON_GUEST_EXIT);
 	} while (fixup_guest_exit(vcpu, &exit_code));
 
 	__sysreg_save_state_nvhe(guest_ctxt);
diff --git a/arch/arm64/kvm/hyp_trace.c b/arch/arm64/kvm/hyp_trace.c
index 0144cd26703e..1ad6a55ba95c 100644
--- a/arch/arm64/kvm/hyp_trace.c
+++ b/arch/arm64/kvm/hyp_trace.c
@@ -364,8 +364,26 @@ static struct trace_remote_callbacks trace_remote_callbacks = {
 	.enable_event		= hyp_trace_enable_event,
 };
 
+static const char *__hyp_enter_exit_reason_str(u8 reason);
+
 #include <asm/kvm_define_hypevents.h>
 
+static const char *__hyp_enter_exit_reason_str(u8 reason)
+{
+	static const char strs[][12] = {
+		"smc",
+		"hvc",
+		"psci",
+		"host_abort",
+		"guest_exit",
+		"eret_host",
+		"eret_guest",
+		"unknown",
+	};
+
+	return strs[min(reason, HYP_REASON_UNKNOWN)];
+}
+
 static void __init hyp_trace_init_events(void)
 {
 	struct hyp_event_id *hyp_event_id = __hyp_event_ids_start;
-- 
2.52.0.107.ga0afd4fd5b-goog
Re: [PATCH v9 28/30] KVM: arm64: Add hyp_enter/hyp_exit events to nVHE/pKVM hyp
Posted by Marc Zyngier 1 month ago 
On Tue, 02 Dec 2025 09:36:21 +0000,
Vincent Donnefort <vdonnefort@google.com> wrote:
> 
> The hyp_enter and hyp_exit events are logged by the hypervisor any time
> it is entered and exited.
> 
> Signed-off-by: Vincent Donnefort <vdonnefort@google.com>
> 
> diff --git a/arch/arm64/include/asm/kvm_hypevents.h b/arch/arm64/include/asm/kvm_hypevents.h
> index d6e033c96c52..268b3cd7a1b2 100644
> --- a/arch/arm64/include/asm/kvm_hypevents.h
> +++ b/arch/arm64/include/asm/kvm_hypevents.h
> @@ -7,4 +7,39 @@
>  #include <nvhe/trace.h>
>  #endif
>  
> +#ifndef __HYP_ENTER_EXIT_REASON
> +#define __HYP_ENTER_EXIT_REASON
> +enum hyp_enter_exit_reason {
> +	HYP_REASON_SMC,
> +	HYP_REASON_HVC,
> +	HYP_REASON_PSCI,
> +	HYP_REASON_HOST_ABORT,
> +	HYP_REASON_GUEST_EXIT,
> +	HYP_REASON_ERET_HOST,
> +	HYP_REASON_ERET_GUEST,
> +	HYP_REASON_UNKNOWN	/* Must be last */
> +};
> +#endif
> +
> +HYP_EVENT(hyp_enter,
> +	HE_PROTO(u8 reason),
> +	HE_STRUCT(
> +		he_field(u8, reason)
> +	),
> +	HE_ASSIGN(
> +		__entry->reason = reason;
> +	),
> +	HE_PRINTK("reason=%s", __hyp_enter_exit_reason_str(__entry->reason))
> +);
> +
> +HYP_EVENT(hyp_exit,
> +	HE_PROTO(u8 reason),
> +	HE_STRUCT(
> +		he_field(u8, reason)
> +	),
> +	HE_ASSIGN(
> +		__entry->reason = reason;
> +	),
> +	HE_PRINTK("reason=%s", __hyp_enter_exit_reason_str(__entry->reason))
> +);
>  #endif
> diff --git a/arch/arm64/kvm/hyp/include/nvhe/arm-smccc.h b/arch/arm64/kvm/hyp/include/nvhe/arm-smccc.h
> new file mode 100644
> index 000000000000..7cd0f701f3c9
> --- /dev/null
> +++ b/arch/arm64/kvm/hyp/include/nvhe/arm-smccc.h
> @@ -0,0 +1,23 @@
> +/* SPDX-License-Identifier: GPL-2.0-only */
> +#ifndef __ARM64_KVM_HYP_NVHE_ARM_SMCCC_H__
> +#define __ARM64_KVM_HYP_NVHE_ARM_SMCCC_H__
> +
> +#include <asm/kvm_hypevents.h>
> +
> +#include <linux/arm-smccc.h>
> +
> +#define hyp_smccc_1_1_smc(...)					\
> +	do {							\
> +		trace_hyp_exit(HYP_REASON_SMC);			\
> +		arm_smccc_1_1_smc(__VA_ARGS__);			\
> +		trace_hyp_enter(HYP_REASON_SMC);		\
> +	} while (0)
> +
> +#define hyp_smccc_1_2_smc(...)					\
> +	do {							\
> +		trace_hyp_exit(HYP_REASON_SMC);			\
> +		arm_smccc_1_2_smc(__VA_ARGS__);			\
> +		trace_hyp_enter(HYP_REASON_SMC);		\
> +	} while (0)
> +
> +#endif /* __ARM64_KVM_HYP_NVHE_ARM_SMCCC_H__ */
> diff --git a/arch/arm64/kvm/hyp/nvhe/ffa.c b/arch/arm64/kvm/hyp/nvhe/ffa.c
> index 58b7d0c477d7..73d79f9de850 100644
> --- a/arch/arm64/kvm/hyp/nvhe/ffa.c
> +++ b/arch/arm64/kvm/hyp/nvhe/ffa.c
> @@ -26,10 +26,10 @@
>   * the duration and are therefore serialised.
>   */
>  
> -#include <linux/arm-smccc.h>
>  #include <linux/arm_ffa.h>
>  #include <asm/kvm_pkvm.h>
>  
> +#include <nvhe/arm-smccc.h>
>  #include <nvhe/ffa.h>
>  #include <nvhe/mem_protect.h>
>  #include <nvhe/memory.h>
> @@ -147,7 +147,7 @@ static int ffa_map_hyp_buffers(u64 ffa_page_count)
>  {
>  	struct arm_smccc_1_2_regs res;
>  
> -	arm_smccc_1_2_smc(&(struct arm_smccc_1_2_regs) {
> +	hyp_smccc_1_2_smc(&(struct arm_smccc_1_2_regs) {
>  		.a0 = FFA_FN64_RXTX_MAP,
>  		.a1 = hyp_virt_to_phys(hyp_buffers.tx),
>  		.a2 = hyp_virt_to_phys(hyp_buffers.rx),
> @@ -161,7 +161,7 @@ static int ffa_unmap_hyp_buffers(void)
>  {
>  	struct arm_smccc_1_2_regs res;
>  
> -	arm_smccc_1_2_smc(&(struct arm_smccc_1_2_regs) {
> +	hyp_smccc_1_2_smc(&(struct arm_smccc_1_2_regs) {
>  		.a0 = FFA_RXTX_UNMAP,
>  		.a1 = HOST_FFA_ID,
>  	}, &res);
> @@ -172,7 +172,7 @@ static int ffa_unmap_hyp_buffers(void)
>  static void ffa_mem_frag_tx(struct arm_smccc_1_2_regs *res, u32 handle_lo,
>  			     u32 handle_hi, u32 fraglen, u32 endpoint_id)
>  {
> -	arm_smccc_1_2_smc(&(struct arm_smccc_1_2_regs) {
> +	hyp_smccc_1_2_smc(&(struct arm_smccc_1_2_regs) {
>  		.a0 = FFA_MEM_FRAG_TX,
>  		.a1 = handle_lo,
>  		.a2 = handle_hi,
> @@ -184,7 +184,7 @@ static void ffa_mem_frag_tx(struct arm_smccc_1_2_regs *res, u32 handle_lo,
>  static void ffa_mem_frag_rx(struct arm_smccc_1_2_regs *res, u32 handle_lo,
>  			     u32 handle_hi, u32 fragoff)
>  {
> -	arm_smccc_1_2_smc(&(struct arm_smccc_1_2_regs) {
> +	hyp_smccc_1_2_smc(&(struct arm_smccc_1_2_regs) {
>  		.a0 = FFA_MEM_FRAG_RX,
>  		.a1 = handle_lo,
>  		.a2 = handle_hi,
> @@ -196,7 +196,7 @@ static void ffa_mem_frag_rx(struct arm_smccc_1_2_regs *res, u32 handle_lo,
>  static void ffa_mem_xfer(struct arm_smccc_1_2_regs *res, u64 func_id, u32 len,
>  			  u32 fraglen)
>  {
> -	arm_smccc_1_2_smc(&(struct arm_smccc_1_2_regs) {
> +	hyp_smccc_1_2_smc(&(struct arm_smccc_1_2_regs) {
>  		.a0 = func_id,
>  		.a1 = len,
>  		.a2 = fraglen,
> @@ -206,7 +206,7 @@ static void ffa_mem_xfer(struct arm_smccc_1_2_regs *res, u64 func_id, u32 len,
>  static void ffa_mem_reclaim(struct arm_smccc_1_2_regs *res, u32 handle_lo,
>  			     u32 handle_hi, u32 flags)
>  {
> -	arm_smccc_1_2_smc(&(struct arm_smccc_1_2_regs) {
> +	hyp_smccc_1_2_smc(&(struct arm_smccc_1_2_regs) {
>  		.a0 = FFA_MEM_RECLAIM,
>  		.a1 = handle_lo,
>  		.a2 = handle_hi,
> @@ -216,7 +216,7 @@ static void ffa_mem_reclaim(struct arm_smccc_1_2_regs *res, u32 handle_lo,
>  
>  static void ffa_retrieve_req(struct arm_smccc_1_2_regs *res, u32 len)
>  {
> -	arm_smccc_1_2_smc(&(struct arm_smccc_1_2_regs) {
> +	hyp_smccc_1_2_smc(&(struct arm_smccc_1_2_regs) {
>  		.a0 = FFA_FN64_MEM_RETRIEVE_REQ,
>  		.a1 = len,
>  		.a2 = len,
> @@ -225,7 +225,7 @@ static void ffa_retrieve_req(struct arm_smccc_1_2_regs *res, u32 len)
>  
>  static void ffa_rx_release(struct arm_smccc_1_2_regs *res)
>  {
> -	arm_smccc_1_2_smc(&(struct arm_smccc_1_2_regs) {
> +	hyp_smccc_1_2_smc(&(struct arm_smccc_1_2_regs) {
>  		.a0 = FFA_RX_RELEASE,
>  	}, res);
>  }
> @@ -728,7 +728,7 @@ static int hyp_ffa_post_init(void)
>  	size_t min_rxtx_sz;
>  	struct arm_smccc_1_2_regs res;
>  
> -	arm_smccc_1_2_smc(&(struct arm_smccc_1_2_regs){
> +	hyp_smccc_1_2_smc(&(struct arm_smccc_1_2_regs){
>  		.a0 = FFA_ID_GET,
>  	}, &res);
>  	if (res.a0 != FFA_SUCCESS)
> @@ -737,7 +737,7 @@ static int hyp_ffa_post_init(void)
>  	if (res.a2 != HOST_FFA_ID)
>  		return -EINVAL;
>  
> -	arm_smccc_1_2_smc(&(struct arm_smccc_1_2_regs){
> +	hyp_smccc_1_2_smc(&(struct arm_smccc_1_2_regs){
>  		.a0 = FFA_FEATURES,
>  		.a1 = FFA_FN64_RXTX_MAP,
>  	}, &res);
> @@ -788,7 +788,7 @@ static void do_ffa_version(struct arm_smccc_1_2_regs *res,
>  	 * first if TEE supports it.
>  	 */
>  	if (FFA_MINOR_VERSION(ffa_req_version) < FFA_MINOR_VERSION(hyp_ffa_version)) {
> -		arm_smccc_1_2_smc(&(struct arm_smccc_1_2_regs) {
> +		hyp_smccc_1_2_smc(&(struct arm_smccc_1_2_regs) {
>  			.a0 = FFA_VERSION,
>  			.a1 = ffa_req_version,
>  		}, res);
> @@ -824,7 +824,7 @@ static void do_ffa_part_get(struct arm_smccc_1_2_regs *res,
>  		goto out_unlock;
>  	}
>  
> -	arm_smccc_1_2_smc(&(struct arm_smccc_1_2_regs) {
> +	hyp_smccc_1_2_smc(&(struct arm_smccc_1_2_regs) {
>  		.a0 = FFA_PARTITION_INFO_GET,
>  		.a1 = uuid0,
>  		.a2 = uuid1,
> @@ -939,7 +939,7 @@ int hyp_ffa_init(void *pages)
>  	if (kvm_host_psci_config.smccc_version < ARM_SMCCC_VERSION_1_2)
>  		return 0;
>  
> -	arm_smccc_1_2_smc(&(struct arm_smccc_1_2_regs) {
> +	hyp_smccc_1_2_smc(&(struct arm_smccc_1_2_regs) {
>  		.a0 = FFA_VERSION,
>  		.a1 = FFA_VERSION_1_2,
>  	}, &res);
> diff --git a/arch/arm64/kvm/hyp/nvhe/hyp-main.c b/arch/arm64/kvm/hyp/nvhe/hyp-main.c
> index 446603cdad7b..ffda4850022f 100644
> --- a/arch/arm64/kvm/hyp/nvhe/hyp-main.c
> +++ b/arch/arm64/kvm/hyp/nvhe/hyp-main.c
> @@ -12,6 +12,7 @@
>  #include <asm/kvm_emulate.h>
>  #include <asm/kvm_host.h>
>  #include <asm/kvm_hyp.h>
> +#include <asm/kvm_hypevents.h>
>  #include <asm/kvm_mmu.h>
>  
>  #include <nvhe/ffa.h>
> @@ -728,7 +729,9 @@ static void handle_host_hcall(struct kvm_cpu_context *host_ctxt)
>  
>  static void default_host_smc_handler(struct kvm_cpu_context *host_ctxt)
>  {
> +	trace_hyp_exit(HYP_REASON_SMC);
>  	__kvm_hyp_host_forward_smc(host_ctxt);
> +	trace_hyp_enter(HYP_REASON_SMC);
>  }
>  
>  static void handle_host_smc(struct kvm_cpu_context *host_ctxt)
> @@ -752,18 +755,24 @@ void handle_trap(struct kvm_cpu_context *host_ctxt)
>  {
>  	u64 esr = read_sysreg_el2(SYS_ESR);
>  
> +
>  	switch (ESR_ELx_EC(esr)) {
>  	case ESR_ELx_EC_HVC64:
> +		trace_hyp_enter(HYP_REASON_HVC);
>  		handle_host_hcall(host_ctxt);
>  		break;
>  	case ESR_ELx_EC_SMC64:
> +		trace_hyp_enter(HYP_REASON_SMC);
>  		handle_host_smc(host_ctxt);
>  		break;
>  	case ESR_ELx_EC_IABT_LOW:
>  	case ESR_ELx_EC_DABT_LOW:
> +		trace_hyp_enter(HYP_REASON_HOST_ABORT);
>  		handle_host_mem_abort(host_ctxt);
>  		break;
>  	default:
>  		BUG();
>  	}
> +
> +	trace_hyp_exit(HYP_REASON_ERET_HOST);
>  }
> diff --git a/arch/arm64/kvm/hyp/nvhe/psci-relay.c b/arch/arm64/kvm/hyp/nvhe/psci-relay.c
> index c3e196fb8b18..58658e09c372 100644
> --- a/arch/arm64/kvm/hyp/nvhe/psci-relay.c
> +++ b/arch/arm64/kvm/hyp/nvhe/psci-relay.c
> @@ -6,11 +6,12 @@
>  
>  #include <asm/kvm_asm.h>
>  #include <asm/kvm_hyp.h>
> +#include <asm/kvm_hypevents.h>
>  #include <asm/kvm_mmu.h>
> -#include <linux/arm-smccc.h>
>  #include <linux/kvm_host.h>
>  #include <uapi/linux/psci.h>
>  
> +#include <nvhe/arm-smccc.h>
>  #include <nvhe/memory.h>
>  #include <nvhe/trap_handler.h>
>  
> @@ -65,7 +66,7 @@ static unsigned long psci_call(unsigned long fn, unsigned long arg0,
>  {
>  	struct arm_smccc_res res;
>  
> -	arm_smccc_1_1_smc(fn, arg0, arg1, arg2, &res);
> +	hyp_smccc_1_1_smc(fn, arg0, arg1, arg2, &res);
>  	return res.a0;
>  }
>  
> @@ -205,6 +206,7 @@ asmlinkage void __noreturn __kvm_host_psci_cpu_entry(bool is_cpu_on)
>  	struct psci_boot_args *boot_args;
>  	struct kvm_cpu_context *host_ctxt;
>  
> +	trace_hyp_enter(HYP_REASON_PSCI);
>  	host_ctxt = host_data_ptr(host_ctxt);
>  
>  	if (is_cpu_on)
> @@ -221,6 +223,7 @@ asmlinkage void __noreturn __kvm_host_psci_cpu_entry(bool is_cpu_on)
>  	write_sysreg_el1(INIT_SCTLR_EL1_MMU_OFF, SYS_SCTLR);
>  	write_sysreg(INIT_PSTATE_EL1, SPSR_EL2);
>  
> +	trace_hyp_exit(HYP_REASON_PSCI);
>  	__host_enter(host_ctxt);
>  }
>  
> diff --git a/arch/arm64/kvm/hyp/nvhe/switch.c b/arch/arm64/kvm/hyp/nvhe/switch.c
> index d3b9ec8a7c28..3dc2bbab4bfc 100644
> --- a/arch/arm64/kvm/hyp/nvhe/switch.c
> +++ b/arch/arm64/kvm/hyp/nvhe/switch.c
> @@ -7,7 +7,6 @@
>  #include <hyp/switch.h>
>  #include <hyp/sysreg-sr.h>
>  
> -#include <linux/arm-smccc.h>
>  #include <linux/kvm_host.h>
>  #include <linux/types.h>
>  #include <linux/jump_label.h>
> @@ -21,6 +20,7 @@
>  #include <asm/kvm_asm.h>
>  #include <asm/kvm_emulate.h>
>  #include <asm/kvm_hyp.h>
> +#include <asm/kvm_hypevents.h>
>  #include <asm/kvm_mmu.h>
>  #include <asm/fpsimd.h>
>  #include <asm/debug-monitors.h>
> @@ -308,10 +308,13 @@ int __kvm_vcpu_run(struct kvm_vcpu *vcpu)
>  	__debug_switch_to_guest(vcpu);
>  
>  	do {
> +		trace_hyp_exit(HYP_REASON_ERET_GUEST);
> +
>  		/* Jump in the fire! */
>  		exit_code = __guest_enter(vcpu);
>  
>  		/* And we're baaack! */
> +		trace_hyp_enter(HYP_REASON_GUEST_EXIT);

nit: seeing these two events back to back makes me think that one of
them is misnamed. Either the first should be GUEST_ENTER, or the
second should be GUEST_EXCEPT... Preference for the former.

>  	} while (fixup_guest_exit(vcpu, &exit_code));
>  
>  	__sysreg_save_state_nvhe(guest_ctxt);
> diff --git a/arch/arm64/kvm/hyp_trace.c b/arch/arm64/kvm/hyp_trace.c
> index 0144cd26703e..1ad6a55ba95c 100644
> --- a/arch/arm64/kvm/hyp_trace.c
> +++ b/arch/arm64/kvm/hyp_trace.c
> @@ -364,8 +364,26 @@ static struct trace_remote_callbacks trace_remote_callbacks = {
>  	.enable_event		= hyp_trace_enable_event,
>  };
>  
> +static const char *__hyp_enter_exit_reason_str(u8 reason);
> +
>  #include <asm/kvm_define_hypevents.h>
>  
> +static const char *__hyp_enter_exit_reason_str(u8 reason)

That's one ugly hack... :-(

> +{
> +	static const char strs[][12] = {
> +		"smc",
> +		"hvc",
> +		"psci",
> +		"host_abort",
> +		"guest_exit",
> +		"eret_host",
> +		"eret_guest",
> +		"unknown",
> +	};
> +
> +	return strs[min(reason, HYP_REASON_UNKNOWN)];
> +}
> +
>  static void __init hyp_trace_init_events(void)
>  {
>  	struct hyp_event_id *hyp_event_id = __hyp_event_ids_start;

Thanks,

	M.

-- 
Without deviation from the norm, progress is not possible.
Re: [PATCH v9 28/30] KVM: arm64: Add hyp_enter/hyp_exit events to nVHE/pKVM hyp
Posted by Steven Rostedt 1 month ago 
On Wed, 07 Jan 2026 14:37:35 +0000
Marc Zyngier <maz@kernel.org> wrote:

> > +static const char *__hyp_enter_exit_reason_str(u8 reason);
> > +
> >  #include <asm/kvm_define_hypevents.h>
> >  
> > +static const char *__hyp_enter_exit_reason_str(u8 reason)  
> 
> That's one ugly hack... :-(

This is basically the way TRACE_EVENT()s are created.

Have a look at include/trace/trace_event.h and include/trace/define_event.h

But I have to warn you. You may need to wear ugly hack proof glasses ;-)

-- Steve

Patchew 2.1-devel-b67e4c2

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