[PATCH v2 3/3] KVM: arm64: Use generic KVM xfer to guest work function

Oliver Upton
2021-07-29T22:09:35Z

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