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From: Anup Patel <apatel@ventanamicro.com>
To: Paolo Bonzini <pbonzini@redhat.com>, Atish Patra <atishp@atishpatra.org>
Cc: Palmer Dabbelt <palmer@dabbelt.com>,
	Paul Walmsley <paul.walmsley@sifive.com>,
	Albert Ou <aou@eecs.berkeley.edu>,
	Alistair Francis <Alistair.Francis@wdc.com>,
	Anup Patel <anup@brainfault.org>,
	kvm@vger.kernel.org, kvm-riscv@lists.infradead.org,
	linux-riscv@lists.infradead.org, linux-kernel@vger.kernel.org,
	Anup Patel <apatel@ventanamicro.com>
Subject: [PATCH 5/6] RISC-V: KVM: Add common kvm_riscv_vcpu_wfi() function
Date: Tue,  1 Feb 2022 13:52:26 +0530	[thread overview]
Message-ID: <20220201082227.361967-6-apatel@ventanamicro.com> (raw)
In-Reply-To: <20220201082227.361967-1-apatel@ventanamicro.com>

The wait for interrupt (WFI) instruction emulation can share the VCPU
halt logic with SBI HSM suspend emulation so this patch adds a common
kvm_riscv_vcpu_wfi() function for this purpose.

Signed-off-by: Anup Patel <apatel@ventanamicro.com>
---
 arch/riscv/include/asm/kvm_host.h |  1 +
 arch/riscv/kvm/vcpu_exit.c        | 22 ++++++++++++++++------
 2 files changed, 17 insertions(+), 6 deletions(-)

diff --git a/arch/riscv/include/asm/kvm_host.h b/arch/riscv/include/asm/kvm_host.h
index 99ef6a120617..78da839657e5 100644
--- a/arch/riscv/include/asm/kvm_host.h
+++ b/arch/riscv/include/asm/kvm_host.h
@@ -228,6 +228,7 @@ void kvm_riscv_stage2_vmid_update(struct kvm_vcpu *vcpu);
 
 void __kvm_riscv_unpriv_trap(void);
 
+void kvm_riscv_vcpu_wfi(struct kvm_vcpu *vcpu);
 unsigned long kvm_riscv_vcpu_unpriv_read(struct kvm_vcpu *vcpu,
 					 bool read_insn,
 					 unsigned long guest_addr,
diff --git a/arch/riscv/kvm/vcpu_exit.c b/arch/riscv/kvm/vcpu_exit.c
index 571f319e995a..aa8af129e4bb 100644
--- a/arch/riscv/kvm/vcpu_exit.c
+++ b/arch/riscv/kvm/vcpu_exit.c
@@ -144,12 +144,7 @@ static int system_opcode_insn(struct kvm_vcpu *vcpu,
 {
 	if ((insn & INSN_MASK_WFI) == INSN_MATCH_WFI) {
 		vcpu->stat.wfi_exit_stat++;
-		if (!kvm_arch_vcpu_runnable(vcpu)) {
-			srcu_read_unlock(&vcpu->kvm->srcu, vcpu->arch.srcu_idx);
-			kvm_vcpu_halt(vcpu);
-			vcpu->arch.srcu_idx = srcu_read_lock(&vcpu->kvm->srcu);
-			kvm_clear_request(KVM_REQ_UNHALT, vcpu);
-		}
+		kvm_riscv_vcpu_wfi(vcpu);
 		vcpu->arch.guest_context.sepc += INSN_LEN(insn);
 		return 1;
 	}
@@ -453,6 +448,21 @@ static int stage2_page_fault(struct kvm_vcpu *vcpu, struct kvm_run *run,
 	return 1;
 }
 
+/**
+ * kvm_riscv_vcpu_wfi -- Emulate wait for interrupt (WFI) behaviour
+ *
+ * @vcpu: The VCPU pointer
+ */
+void kvm_riscv_vcpu_wfi(struct kvm_vcpu *vcpu)
+{
+	if (!kvm_arch_vcpu_runnable(vcpu)) {
+		srcu_read_unlock(&vcpu->kvm->srcu, vcpu->arch.srcu_idx);
+		kvm_vcpu_halt(vcpu);
+		vcpu->arch.srcu_idx = srcu_read_lock(&vcpu->kvm->srcu);
+		kvm_clear_request(KVM_REQ_UNHALT, vcpu);
+	}
+}
+
 /**
  * kvm_riscv_vcpu_unpriv_read -- Read machine word from Guest memory
  *
-- 
2.25.1


  parent reply	other threads:[~2022-02-01  8:24 UTC|newest]

Thread overview: 14+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2022-02-01  8:22 [PATCH 0/6] KVM RISC-V SBI v0.3 support Anup Patel
2022-02-01  8:22 ` [PATCH 1/6] RISC-V: KVM: Upgrade SBI spec version to v0.3 Anup Patel
2022-02-22 23:53   ` Atish Patra
2022-02-01  8:22 ` [PATCH 2/6] RISC-V: KVM: Add common kvm_riscv_vcpu_sbi_system_reset() function Anup Patel
2022-02-22 23:54   ` Atish Patra
2022-02-01  8:22 ` [PATCH 3/6] RISC-V: KVM: Implement SBI v0.3 SRST extension Anup Patel
2022-02-22 23:56   ` Atish Patra
2022-02-01  8:22 ` [PATCH 4/6] RISC-V: Add SBI HSM suspend related defines Anup Patel
2022-02-23  0:00   ` Atish Patra
2022-02-01  8:22 ` Anup Patel [this message]
2022-02-23  0:01   ` [PATCH 5/6] RISC-V: KVM: Add common kvm_riscv_vcpu_wfi() function Atish Patra
2022-02-01  8:22 ` [PATCH 6/6] RISC-V: KVM: Implement SBI HSM suspend call Anup Patel
2022-02-23  3:37   ` Atish Patra
2022-03-08  5:57 ` [PATCH 0/6] KVM RISC-V SBI v0.3 support Anup Patel

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