[PATCH 3/3] KVM: arm64: Use generic KVM xfer to guest work function

From: Oliver Upton <oupton@google.com>
To: kvmarm@lists.cs.columbia.edu
Cc: kvm@vger.kernel.org, linux-kernel@vger.kernel.org,
	Paolo Bonzini <pbonzini@redhat.com>,
	Marc Zyngier <maz@kernel.org>, James Morse <james.morse@arm.com>,
	Alexandru Elisei <alexandru.elisei@arm.com>,
	Suzuki K Poulose <suzuki.poulose@arm.com>,
	Catalin Marinas <catalin.marinas@arm.com>,
	Will Deacon <will@kernel.org>,
	Thomas Gleixner <tglx@linutronix.de>,
	Peter Zijlstra <peterz@infradead.org>,
	Andy Lutomirski <luto@kernel.org>,
	linux-arm-kernel@lists.infradead.org,
	Peter Shier <pshier@google.com>,
	Shakeel Butt <shakeelb@google.com>,
	Guangyu Shi <guangyus@google.com>,
	Oliver Upton <oupton@google.com>
Subject: [PATCH 3/3] KVM: arm64: Use generic KVM xfer to guest work function
Date: Thu, 29 Jul 2021 19:56:32 +0000	[thread overview]
Message-ID: <20210729195632.489978-4-oupton@google.com> (raw)
In-Reply-To: <20210729195632.489978-1-oupton@google.com>

Clean up handling of checks for pending work by switching to the generic
infrastructure to do so.

We pick up handling for TIF_NOTIFY_RESUME from this switch, meaning that
task work will be correctly handled.

Signed-off-by: Oliver Upton <oupton@google.com>
---
 arch/arm64/kvm/Kconfig |  1 +
 arch/arm64/kvm/arm.c   | 27 ++++++++++++++-------------
 2 files changed, 15 insertions(+), 13 deletions(-)

diff --git a/arch/arm64/kvm/Kconfig b/arch/arm64/kvm/Kconfig
index a4eba0908bfa..8bc1fac5fa26 100644
--- a/arch/arm64/kvm/Kconfig
+++ b/arch/arm64/kvm/Kconfig
@@ -26,6 +26,7 @@ menuconfig KVM
 	select HAVE_KVM_ARCH_TLB_FLUSH_ALL
 	select KVM_MMIO
 	select KVM_GENERIC_DIRTYLOG_READ_PROTECT
+	select KVM_XFER_TO_GUEST_WORK
 	select SRCU
 	select KVM_VFIO
 	select HAVE_KVM_EVENTFD
diff --git a/arch/arm64/kvm/arm.c b/arch/arm64/kvm/arm.c
index 60d0a546d7fd..9762e2129813 100644
--- a/arch/arm64/kvm/arm.c
+++ b/arch/arm64/kvm/arm.c
@@ -6,6 +6,7 @@
 
 #include <linux/bug.h>
 #include <linux/cpu_pm.h>
+#include <linux/entry-kvm.h>
 #include <linux/errno.h>
 #include <linux/err.h>
 #include <linux/kvm_host.h>
@@ -714,6 +715,13 @@ static bool vcpu_mode_is_bad_32bit(struct kvm_vcpu *vcpu)
 		static_branch_unlikely(&arm64_mismatched_32bit_el0);
 }
 
+static bool kvm_vcpu_exit_request(struct kvm_vcpu *vcpu)
+{
+	return kvm_request_pending(vcpu) ||
+			need_new_vmid_gen(&vcpu->arch.hw_mmu->vmid) ||
+			xfer_to_guest_mode_work_pending();
+}
+
 /**
  * kvm_arch_vcpu_ioctl_run - the main VCPU run function to execute guest code
  * @vcpu:	The VCPU pointer
@@ -757,7 +765,11 @@ int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu)
 		/*
 		 * Check conditions before entering the guest
 		 */
-		cond_resched();
+		if (__xfer_to_guest_mode_work_pending()) {
+			ret = xfer_to_guest_mode_handle_work(vcpu);
+			if (!ret)
+				ret = 1;
+		}
 
 		update_vmid(&vcpu->arch.hw_mmu->vmid);
 
@@ -776,16 +788,6 @@ int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu)
 
 		kvm_vgic_flush_hwstate(vcpu);
 
-		/*
-		 * Exit if we have a signal pending so that we can deliver the
-		 * signal to user space.
-		 */
-		if (signal_pending(current)) {
-			ret = -EINTR;
-			run->exit_reason = KVM_EXIT_INTR;
-			++vcpu->stat.signal_exits;
-		}
-
 		/*
 		 * If we're using a userspace irqchip, then check if we need
 		 * to tell a userspace irqchip about timer or PMU level
@@ -809,8 +811,7 @@ int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu)
 		 */
 		smp_store_mb(vcpu->mode, IN_GUEST_MODE);
 
-		if (ret <= 0 || need_new_vmid_gen(&vcpu->arch.hw_mmu->vmid) ||
-		    kvm_request_pending(vcpu)) {
+		if (ret <= 0 || kvm_vcpu_exit_request(vcpu)) {
 			vcpu->mode = OUTSIDE_GUEST_MODE;
 			isb(); /* Ensure work in x_flush_hwstate is committed */
 			kvm_pmu_sync_hwstate(vcpu);
-- 
2.32.0.554.ge1b32706d8-goog

