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From:   Tianrui Zhao <zhaotianrui@loongson.cn>
To:     Paolo Bonzini <pbonzini@redhat.com>
Cc:     Huacai Chen <chenhuacai@kernel.org>,
        WANG Xuerui <kernel@xen0n.name>,
        Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        loongarch@lists.linux.dev, linux-kernel@vger.kernel.org,
        kvm@vger.kernel.org, Jens Axboe <axboe@kernel.dk>,
        Mark Brown <broonie@kernel.org>,
        Alex Deucher <alexander.deucher@amd.com>,
        Oliver Upton <oliver.upton@linux.dev>, maobibo@loongson.cn,
        Xi Ruoyao <xry111@xry111.site>, zhaotianrui@loongson.cn
Subject: [PATCH v6 07/30] LoongArch: KVM: Implement vcpu run interface
Date:   Wed, 12 Apr 2023 16:30:00 +0800
Message-Id: <20230412083023.1693910-8-zhaotianrui@loongson.cn>
In-Reply-To: <20230412083023.1693910-1-zhaotianrui@loongson.cn>
References: <20230412083023.1693910-1-zhaotianrui@loongson.cn>
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Precedence: bulk

Implement vcpu run interface, handling mmio, iocsr reading fault
and deliver interrupt, lose fpu before vcpu enter guest.

Signed-off-by: Tianrui Zhao <zhaotianrui@loongson.cn>
---
 arch/loongarch/kvm/vcpu.c | 86 +++++++++++++++++++++++++++++++++++++++
 1 file changed, 86 insertions(+)

diff --git a/arch/loongarch/kvm/vcpu.c b/arch/loongarch/kvm/vcpu.c
index 7af2ff64b8c7..bc9e3889fee1 100644
--- a/arch/loongarch/kvm/vcpu.c
+++ b/arch/loongarch/kvm/vcpu.c
@@ -18,6 +18,44 @@ int kvm_arch_vcpu_precreate(struct kvm *kvm, unsigned int id)
 	return 0;
 }
 
+/* Returns 1 if the guest TLB may be clobbered */
+static int _kvm_check_requests(struct kvm_vcpu *vcpu, int cpu)
+{
+	int ret = 0;
+
+	if (!kvm_request_pending(vcpu))
+		return 0;
+
+	if (kvm_check_request(KVM_REQ_TLB_FLUSH, vcpu)) {
+		/* Drop vpid for this VCPU */
+		vcpu->arch.vpid = 0;
+		/* This will clobber guest TLB contents too */
+		ret = 1;
+	}
+
+	return ret;
+}
+
+static void kvm_pre_enter_guest(struct kvm_vcpu *vcpu)
+{
+	int cpu;
+
+	/*
+	 * handle vcpu timer, interrupts, check requests and
+	 * check vmid before vcpu enter guest
+	 */
+	kvm_acquire_timer(vcpu);
+	_kvm_deliver_intr(vcpu);
+	/* make sure the vcpu mode has been written */
+	smp_store_mb(vcpu->mode, IN_GUEST_MODE);
+	cpu = smp_processor_id();
+	_kvm_check_requests(vcpu, cpu);
+	_kvm_check_vmid(vcpu, cpu);
+	vcpu->arch.host_eentry = csr_read64(LOONGARCH_CSR_EENTRY);
+	/* clear KVM_LARCH_CSR as csr will change when enter guest */
+	vcpu->arch.aux_inuse &= ~KVM_LARCH_CSR;
+}
+
 int kvm_arch_vcpu_create(struct kvm_vcpu *vcpu)
 {
 	unsigned long timer_hz;
@@ -87,3 +125,51 @@ void kvm_arch_vcpu_destroy(struct kvm_vcpu *vcpu)
 			context->last_vcpu = NULL;
 	}
 }
+
+int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu)
+{
+	int r = -EINTR;
+	struct kvm_run *run = vcpu->run;
+
+	vcpu_load(vcpu);
+
+	kvm_sigset_activate(vcpu);
+
+	if (vcpu->mmio_needed) {
+		if (!vcpu->mmio_is_write)
+			_kvm_complete_mmio_read(vcpu, run);
+		vcpu->mmio_needed = 0;
+	}
+
+	if (run->exit_reason == KVM_EXIT_LOONGARCH_IOCSR) {
+		if (!run->iocsr_io.is_write)
+			_kvm_complete_iocsr_read(vcpu, run);
+	}
+
+	/* clear exit_reason */
+	run->exit_reason = KVM_EXIT_UNKNOWN;
+	if (run->immediate_exit)
+		goto out;
+
+	lose_fpu(1);
+
+	local_irq_disable();
+	guest_timing_enter_irqoff();
+
+	kvm_pre_enter_guest(vcpu);
+	trace_kvm_enter(vcpu);
+
+	guest_state_enter_irqoff();
+	r = kvm_loongarch_ops->enter_guest(run, vcpu);
+
+	/* guest_state_exit_irqoff() already done.  */
+	trace_kvm_out(vcpu);
+	guest_timing_exit_irqoff();
+	local_irq_enable();
+
+out:
+	kvm_sigset_deactivate(vcpu);
+
+	vcpu_put(vcpu);
+	return r;
+}
-- 
2.31.1