linux-kernel - [PATCH v12 22/31] LoongArch: KVM: Implement handle idle exception

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-Id: <20230530015223.147755-23-zhaotianrui@loongson.cn>
Date:   Tue, 30 May 2023 09:52:14 +0800
From:   Tianrui Zhao <zhaotianrui@...ngson.cn>
To:     linux-kernel@...r.kernel.org, kvm@...r.kernel.org
Cc:     Paolo Bonzini <pbonzini@...hat.com>,
        Huacai Chen <chenhuacai@...nel.org>,
        WANG Xuerui <kernel@...0n.name>,
        Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
        loongarch@...ts.linux.dev, Jens Axboe <axboe@...nel.dk>,
        Mark Brown <broonie@...nel.org>,
        Alex Deucher <alexander.deucher@....com>,
        Oliver Upton <oliver.upton@...ux.dev>, maobibo@...ngson.cn,
        Xi Ruoyao <xry111@...111.site>, zhaotianrui@...ngson.cn
Subject: [PATCH v12 22/31] LoongArch: KVM: Implement handle idle exception

Implement kvm handle LoongArch vcpu idle exception, using kvm_vcpu_block
to emulate it.

Signed-off-by: Tianrui Zhao <zhaotianrui@...ngson.cn>
---
 arch/loongarch/kvm/exit.c | 20 ++++++++++++++++++++
 1 file changed, 20 insertions(+)

diff --git a/arch/loongarch/kvm/exit.c b/arch/loongarch/kvm/exit.c
index bd33fe0c6424..3fdb42939a05 100644
--- a/arch/loongarch/kvm/exit.c
+++ b/arch/loongarch/kvm/exit.c
@@ -188,3 +188,23 @@ int _kvm_complete_iocsr_read(struct kvm_vcpu *vcpu, struct kvm_run *run)
 
 	return er;
 }
+
+int _kvm_emu_idle(struct kvm_vcpu *vcpu)
+{
+	++vcpu->stat.idle_exits;
+	trace_kvm_exit_idle(vcpu, KVM_TRACE_EXIT_IDLE);
+
+	if (!kvm_arch_vcpu_runnable(vcpu)) {
+		/*
+		 * Switch to the software timer before halt-polling/blocking as
+		 * the guest's timer may be a break event for the vCPU, and the
+		 * hypervisor timer runs only when the CPU is in guest mode.
+		 * Switch before halt-polling so that KVM recognizes an expired
+		 * timer before blocking.
+		 */
+		kvm_save_timer(vcpu);
+		kvm_vcpu_block(vcpu);
+	}
+
+	return EMULATE_DONE;
+}
-- 
2.39.1