linux-kernel - [RFC PATCH v4 28/39] KVM: arm64: nVHE: Save PMSCR

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Message-Id: <20210825161815.266051-29-alexandru.elisei@arm.com>
Date:   Wed, 25 Aug 2021 17:18:04 +0100
From:   Alexandru Elisei <alexandru.elisei@....com>
To:     maz@...nel.org, james.morse@....com, suzuki.poulose@....com,
        linux-arm-kernel@...ts.infradead.org, kvmarm@...ts.cs.columbia.edu,
        will@...nel.org, linux-kernel@...r.kernel.org
Subject: [RFC PATCH v4 28/39] KVM: arm64: nVHE: Save PMSCR_EL1 to the host context

The SPE registers are now part of the KVM register context, use the host
context to save the value of PMSCR_EL1 instead of a dedicated field in
host_debug_state.

Signed-off-by: Alexandru Elisei <alexandru.elisei@....com>
---
 arch/arm64/include/asm/kvm_host.h  |  2 --
 arch/arm64/include/asm/kvm_hyp.h   |  6 ++++--
 arch/arm64/kvm/hyp/nvhe/debug-sr.c | 10 ++++++----
 arch/arm64/kvm/hyp/nvhe/switch.c   |  4 ++--
 4 files changed, 12 insertions(+), 10 deletions(-)

diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h
index 4c0d3d5ba285..351b77dc7732 100644
--- a/arch/arm64/include/asm/kvm_host.h
+++ b/arch/arm64/include/asm/kvm_host.h
@@ -356,8 +356,6 @@ 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;
diff --git a/arch/arm64/include/asm/kvm_hyp.h b/arch/arm64/include/asm/kvm_hyp.h
index 657d0c94cf82..48619c2c0dc6 100644
--- a/arch/arm64/include/asm/kvm_hyp.h
+++ b/arch/arm64/include/asm/kvm_hyp.h
@@ -84,8 +84,10 @@ 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_vcpu *vcpu,
+				    struct kvm_cpu_context *host_ctxt);
+void __debug_restore_host_buffers_nvhe(struct kvm_vcpu *vcpu,
+				       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 7d3f25868cae..6db58722f045 100644
--- a/arch/arm64/kvm/hyp/nvhe/debug-sr.c
+++ b/arch/arm64/kvm/hyp/nvhe/debug-sr.c
@@ -81,11 +81,12 @@ static void __debug_restore_trace(u64 trfcr_el1)
 	write_sysreg_s(trfcr_el1, SYS_TRFCR_EL1);
 }
 
-void __debug_save_host_buffers_nvhe(struct kvm_vcpu *vcpu)
+void __debug_save_host_buffers_nvhe(struct kvm_vcpu *vcpu,
+				    struct kvm_cpu_context *host_ctxt)
 {
 	/* Disable and flush SPE data generation */
 	if (vcpu->arch.flags & KVM_ARM64_DEBUG_STATE_SAVE_SPE)
-		__debug_save_spe(&vcpu->arch.host_debug_state.pmscr_el1);
+		__debug_save_spe(__ctxt_sys_reg(host_ctxt, PMSCR_EL1));
 	/* Disable and flush Self-Hosted Trace generation */
 	if (vcpu->arch.flags & KVM_ARM64_DEBUG_STATE_SAVE_TRBE)
 		__debug_save_trace(&vcpu->arch.host_debug_state.trfcr_el1);
@@ -96,10 +97,11 @@ 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_vcpu *vcpu,
+				       struct kvm_cpu_context *host_ctxt)
 {
 	if (vcpu->arch.flags & KVM_ARM64_DEBUG_STATE_SAVE_SPE)
-		__debug_restore_spe(vcpu->arch.host_debug_state.pmscr_el1);
+		__debug_restore_spe(ctxt_sys_reg(host_ctxt, PMSCR_EL1));
 	if (vcpu->arch.flags & KVM_ARM64_DEBUG_STATE_SAVE_TRBE)
 		__debug_restore_trace(vcpu->arch.host_debug_state.trfcr_el1);
 }
diff --git a/arch/arm64/kvm/hyp/nvhe/switch.c b/arch/arm64/kvm/hyp/nvhe/switch.c
index 0c70d897a493..04d654e71a6e 100644
--- a/arch/arm64/kvm/hyp/nvhe/switch.c
+++ b/arch/arm64/kvm/hyp/nvhe/switch.c
@@ -200,7 +200,7 @@ 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(vcpu, host_ctxt);
 
 	__kvm_adjust_pc(vcpu);
 
@@ -248,7 +248,7 @@ 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(vcpu, host_ctxt);
 
 	if (pmu_switch_needed)
 		__pmu_switch_to_host(host_ctxt);
-- 
2.33.0