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[v2,10/13] RISC-V: KVM: Use nacl_csr_xyz() for accessing AIA CSRs

Message ID 20241020194734.58686-11-apatel@ventanamicro.com (mailing list archive)
State New
Headers show
Series Accelerate KVM RISC-V when running as a guest | expand

Commit Message

Anup Patel Oct. 20, 2024, 7:47 p.m. UTC 
When running under some other hypervisor, prefer nacl_csr_xyz()
for accessing AIA CSRs in the run-loop. This makes CSR access
faster whenever SBI nested acceleration is available.

Signed-off-by: Anup Patel <apatel@ventanamicro.com>
Reviewed-by: Atish Patra <atishp@rivosinc.com>
---
 arch/riscv/kvm/aia.c | 97 ++++++++++++++++++++++++++++----------------
 1 file changed, 63 insertions(+), 34 deletions(-)
diff mbox series

Patch

diff --git a/arch/riscv/kvm/aia.c b/arch/riscv/kvm/aia.c
index 8ffae0330c89..dcced4db7fe8 100644
--- a/arch/riscv/kvm/aia.c
+++ b/arch/riscv/kvm/aia.c
@@ -16,6 +16,7 @@ 
 #include <linux/percpu.h>
 #include <linux/spinlock.h>
 #include <asm/cpufeature.h>
+#include <asm/kvm_nacl.h>
 
 struct aia_hgei_control {
 	raw_spinlock_t lock;
@@ -88,7 +89,7 @@  void kvm_riscv_vcpu_aia_sync_interrupts(struct kvm_vcpu *vcpu)
 	struct kvm_vcpu_aia_csr *csr = &vcpu->arch.aia_context.guest_csr;
 
 	if (kvm_riscv_aia_available())
-		csr->vsieh = csr_read(CSR_VSIEH);
+		csr->vsieh = ncsr_read(CSR_VSIEH);
 }
 #endif
 
@@ -115,7 +116,7 @@  bool kvm_riscv_vcpu_aia_has_interrupts(struct kvm_vcpu *vcpu, u64 mask)
 
 	hgei = aia_find_hgei(vcpu);
 	if (hgei > 0)
-		return !!(csr_read(CSR_HGEIP) & BIT(hgei));
+		return !!(ncsr_read(CSR_HGEIP) & BIT(hgei));
 
 	return false;
 }
@@ -128,45 +129,73 @@  void kvm_riscv_vcpu_aia_update_hvip(struct kvm_vcpu *vcpu)
 		return;
 
 #ifdef CONFIG_32BIT
-	csr_write(CSR_HVIPH, vcpu->arch.aia_context.guest_csr.hviph);
+	ncsr_write(CSR_HVIPH, vcpu->arch.aia_context.guest_csr.hviph);
 #endif
-	csr_write(CSR_HVICTL, aia_hvictl_value(!!(csr->hvip & BIT(IRQ_VS_EXT))));
+	ncsr_write(CSR_HVICTL, aia_hvictl_value(!!(csr->hvip & BIT(IRQ_VS_EXT))));
 }
 
 void kvm_riscv_vcpu_aia_load(struct kvm_vcpu *vcpu, int cpu)
 {
 	struct kvm_vcpu_aia_csr *csr = &vcpu->arch.aia_context.guest_csr;
+	void *nsh;
 
 	if (!kvm_riscv_aia_available())
 		return;
 
-	csr_write(CSR_VSISELECT, csr->vsiselect);
-	csr_write(CSR_HVIPRIO1, csr->hviprio1);
-	csr_write(CSR_HVIPRIO2, csr->hviprio2);
+	if (kvm_riscv_nacl_sync_csr_available()) {
+		nsh = nacl_shmem();
+		nacl_csr_write(nsh, CSR_VSISELECT, csr->vsiselect);
+		nacl_csr_write(nsh, CSR_HVIPRIO1, csr->hviprio1);
+		nacl_csr_write(nsh, CSR_HVIPRIO2, csr->hviprio2);
+#ifdef CONFIG_32BIT
+		nacl_csr_write(nsh, CSR_VSIEH, csr->vsieh);
+		nacl_csr_write(nsh, CSR_HVIPH, csr->hviph);
+		nacl_csr_write(nsh, CSR_HVIPRIO1H, csr->hviprio1h);
+		nacl_csr_write(nsh, CSR_HVIPRIO2H, csr->hviprio2h);
+#endif
+	} else {
+		csr_write(CSR_VSISELECT, csr->vsiselect);
+		csr_write(CSR_HVIPRIO1, csr->hviprio1);
+		csr_write(CSR_HVIPRIO2, csr->hviprio2);
 #ifdef CONFIG_32BIT
-	csr_write(CSR_VSIEH, csr->vsieh);
-	csr_write(CSR_HVIPH, csr->hviph);
-	csr_write(CSR_HVIPRIO1H, csr->hviprio1h);
-	csr_write(CSR_HVIPRIO2H, csr->hviprio2h);
+		csr_write(CSR_VSIEH, csr->vsieh);
+		csr_write(CSR_HVIPH, csr->hviph);
+		csr_write(CSR_HVIPRIO1H, csr->hviprio1h);
+		csr_write(CSR_HVIPRIO2H, csr->hviprio2h);
 #endif
+	}
 }
 
 void kvm_riscv_vcpu_aia_put(struct kvm_vcpu *vcpu)
 {
 	struct kvm_vcpu_aia_csr *csr = &vcpu->arch.aia_context.guest_csr;
+	void *nsh;
 
 	if (!kvm_riscv_aia_available())
 		return;
 
-	csr->vsiselect = csr_read(CSR_VSISELECT);
-	csr->hviprio1 = csr_read(CSR_HVIPRIO1);
-	csr->hviprio2 = csr_read(CSR_HVIPRIO2);
+	if (kvm_riscv_nacl_available()) {
+		nsh = nacl_shmem();
+		csr->vsiselect = nacl_csr_read(nsh, CSR_VSISELECT);
+		csr->hviprio1 = nacl_csr_read(nsh, CSR_HVIPRIO1);
+		csr->hviprio2 = nacl_csr_read(nsh, CSR_HVIPRIO2);
 #ifdef CONFIG_32BIT
-	csr->vsieh = csr_read(CSR_VSIEH);
-	csr->hviph = csr_read(CSR_HVIPH);
-	csr->hviprio1h = csr_read(CSR_HVIPRIO1H);
-	csr->hviprio2h = csr_read(CSR_HVIPRIO2H);
+		csr->vsieh = nacl_csr_read(nsh, CSR_VSIEH);
+		csr->hviph = nacl_csr_read(nsh, CSR_HVIPH);
+		csr->hviprio1h = nacl_csr_read(nsh, CSR_HVIPRIO1H);
+		csr->hviprio2h = nacl_csr_read(nsh, CSR_HVIPRIO2H);
 #endif
+	} else {
+		csr->vsiselect = csr_read(CSR_VSISELECT);
+		csr->hviprio1 = csr_read(CSR_HVIPRIO1);
+		csr->hviprio2 = csr_read(CSR_HVIPRIO2);
+#ifdef CONFIG_32BIT
+		csr->vsieh = csr_read(CSR_VSIEH);
+		csr->hviph = csr_read(CSR_HVIPH);
+		csr->hviprio1h = csr_read(CSR_HVIPRIO1H);
+		csr->hviprio2h = csr_read(CSR_HVIPRIO2H);
+#endif
+	}
 }
 
 int kvm_riscv_vcpu_aia_get_csr(struct kvm_vcpu *vcpu,
@@ -250,20 +279,20 @@  static u8 aia_get_iprio8(struct kvm_vcpu *vcpu, unsigned int irq)
 
 	switch (bitpos / BITS_PER_LONG) {
 	case 0:
-		hviprio = csr_read(CSR_HVIPRIO1);
+		hviprio = ncsr_read(CSR_HVIPRIO1);
 		break;
 	case 1:
 #ifndef CONFIG_32BIT
-		hviprio = csr_read(CSR_HVIPRIO2);
+		hviprio = ncsr_read(CSR_HVIPRIO2);
 		break;
 #else
-		hviprio = csr_read(CSR_HVIPRIO1H);
+		hviprio = ncsr_read(CSR_HVIPRIO1H);
 		break;
 	case 2:
-		hviprio = csr_read(CSR_HVIPRIO2);
+		hviprio = ncsr_read(CSR_HVIPRIO2);
 		break;
 	case 3:
-		hviprio = csr_read(CSR_HVIPRIO2H);
+		hviprio = ncsr_read(CSR_HVIPRIO2H);
 		break;
 #endif
 	default:
@@ -283,20 +312,20 @@  static void aia_set_iprio8(struct kvm_vcpu *vcpu, unsigned int irq, u8 prio)
 
 	switch (bitpos / BITS_PER_LONG) {
 	case 0:
-		hviprio = csr_read(CSR_HVIPRIO1);
+		hviprio = ncsr_read(CSR_HVIPRIO1);
 		break;
 	case 1:
 #ifndef CONFIG_32BIT
-		hviprio = csr_read(CSR_HVIPRIO2);
+		hviprio = ncsr_read(CSR_HVIPRIO2);
 		break;
 #else
-		hviprio = csr_read(CSR_HVIPRIO1H);
+		hviprio = ncsr_read(CSR_HVIPRIO1H);
 		break;
 	case 2:
-		hviprio = csr_read(CSR_HVIPRIO2);
+		hviprio = ncsr_read(CSR_HVIPRIO2);
 		break;
 	case 3:
-		hviprio = csr_read(CSR_HVIPRIO2H);
+		hviprio = ncsr_read(CSR_HVIPRIO2H);
 		break;
 #endif
 	default:
@@ -308,20 +337,20 @@  static void aia_set_iprio8(struct kvm_vcpu *vcpu, unsigned int irq, u8 prio)
 
 	switch (bitpos / BITS_PER_LONG) {
 	case 0:
-		csr_write(CSR_HVIPRIO1, hviprio);
+		ncsr_write(CSR_HVIPRIO1, hviprio);
 		break;
 	case 1:
 #ifndef CONFIG_32BIT
-		csr_write(CSR_HVIPRIO2, hviprio);
+		ncsr_write(CSR_HVIPRIO2, hviprio);
 		break;
 #else
-		csr_write(CSR_HVIPRIO1H, hviprio);
+		ncsr_write(CSR_HVIPRIO1H, hviprio);
 		break;
 	case 2:
-		csr_write(CSR_HVIPRIO2, hviprio);
+		ncsr_write(CSR_HVIPRIO2, hviprio);
 		break;
 	case 3:
-		csr_write(CSR_HVIPRIO2H, hviprio);
+		ncsr_write(CSR_HVIPRIO2H, hviprio);
 		break;
 #endif
 	default:
@@ -377,7 +406,7 @@  int kvm_riscv_vcpu_aia_rmw_ireg(struct kvm_vcpu *vcpu, unsigned int csr_num,
 		return KVM_INSN_ILLEGAL_TRAP;
 
 	/* First try to emulate in kernel space */
-	isel = csr_read(CSR_VSISELECT) & ISELECT_MASK;
+	isel = ncsr_read(CSR_VSISELECT) & ISELECT_MASK;
 	if (isel >= ISELECT_IPRIO0 && isel <= ISELECT_IPRIO15)
 		return aia_rmw_iprio(vcpu, isel, val, new_val, wr_mask);
 	else if (isel >= IMSIC_FIRST && isel <= IMSIC_LAST &&