On an unhandled IO memory abort, use the kvm_io_bus_* API in order to
handle the MMIO access through any registered read/write callbacks. This
is a dependency for eventfd support (ioeventfd and irqfd).
However, accesses to the VGIC are still left implemented independently,
since the kvm_io_bus_* API doesn't pass the VCPU pointer doing the access.
Signed-off-by: Antonios Motakis <a.mota...@virtualopensystems.com>
Signed-off-by: Nikolay Nikolaev <n.nikol...@virtualopensystems.com>
---
arch/arm/kvm/mmio.c | 32 ++++++++++++++++++++++++++++++++
virt/kvm/arm/vgic.c | 5 ++++-
2 files changed, 36 insertions(+), 1 deletion(-)
diff --git a/arch/arm/kvm/mmio.c b/arch/arm/kvm/mmio.c
index 4cb5a93..1d17831 100644
--- a/arch/arm/kvm/mmio.c
+++ b/arch/arm/kvm/mmio.c
@@ -162,6 +162,35 @@ static int decode_hsr(struct kvm_vcpu *vcpu, phys_addr_t
fault_ipa,
return 0;
}
+/**
+ * kvm_handle_mmio - handle an in-kernel MMIO access
+ * @vcpu: pointer to the vcpu performing the access
+ * @run: pointer to the kvm_run structure
+ * @mmio: pointer to the data describing the access
+ *
+ * returns true if the MMIO access has been performed in kernel space,
+ * and false if it needs to be emulated in user space.
+ */
+static bool handle_kernel_mmio(struct kvm_vcpu *vcpu, struct kvm_run *run,
+ struct kvm_exit_mmio *mmio)
+{
+ int ret;
+ if (mmio->is_write) {
+ ret = kvm_io_bus_write(vcpu->kvm, KVM_MMIO_BUS, mmio->phys_addr,
+ mmio->len, &mmio->data);
+
+ } else {
+ ret = kvm_io_bus_read(vcpu->kvm, KVM_MMIO_BUS, mmio->phys_addr,
+ mmio->len, &mmio->data);
+ }
+ if (!ret) {
+ kvm_prepare_mmio(run, mmio);
+ kvm_handle_mmio_return(vcpu, run);
+ }
+
+ return !ret;
+}
+
int io_mem_abort(struct kvm_vcpu *vcpu, struct kvm_run *run,
phys_addr_t fault_ipa)
{
@@ -200,6 +229,9 @@ int io_mem_abort(struct kvm_vcpu *vcpu, struct kvm_run *run,
if (vgic_handle_mmio(vcpu, run, &mmio))
return 1;
+ if (handle_kernel_mmio(vcpu, run, &mmio))
+ return 1;
+
kvm_prepare_mmio(run, &mmio);
return 0;
}
diff --git a/virt/kvm/arm/vgic.c b/virt/kvm/arm/vgic.c
index 8ca405c..afdecc3 100644
--- a/virt/kvm/arm/vgic.c
+++ b/virt/kvm/arm/vgic.c
@@ -849,13 +849,16 @@ struct mmio_range *find_matching_range(const struct
mmio_range *ranges,
}
/**
- * vgic_handle_mmio - handle an in-kernel MMIO access
+ * vgic_handle_mmio - handle an in-kernel vgic MMIO access
* @vcpu: pointer to the vcpu performing the access
* @run: pointer to the kvm_run structure
* @mmio: pointer to the data describing the access
*
* returns true if the MMIO access has been performed in kernel space,
* and false if it needs to be emulated in user space.
+ *
+ * This is handled outside of kvm_handle_mmio because the kvm_io_bus only
+ * passes the VM pointer, while we need the VCPU performing the access.
*/
bool vgic_handle_mmio(struct kvm_vcpu *vcpu, struct kvm_run *run,
struct kvm_exit_mmio *mmio)
--
1.8.3.2
--
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