KVM: arm/arm64: rework MMIO abort handling to use KVM MMIO bus

Currently we have struct kvm_exit_mmio for encapsulating MMIO abort
data to be passed on from syndrome decoding all the way down to the
VGIC register handlers. Now as we switch the MMIO handling to be
routed through the KVM MMIO bus, it does not make sense anymore to
use that structure already from the beginning. So we keep the data in
local variables until we put them into the kvm_io_bus framework.
Then we fill kvm_exit_mmio in the VGIC only, making it a VGIC private
structure. On that way we replace the data buffer in that structure
with a pointer pointing to a single location in a local variable, so
we get rid of some copying on the way.
With all of the virtual GIC emulation code now being registered with
the kvm_io_bus, we can remove all of the old MMIO handling code and
its dispatching functionality.

I didn't bother to rename kvm_exit_mmio (to vgic_mmio or something),
because that touches a lot of code lines without any good reason.

This is based on an original patch by Nikolay.

Signed-off-by: Andre Przywara <andre.przywara@arm.com>
Cc: Nikolay Nikolaev <n.nikolaev@virtualopensystems.com>
Reviewed-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>

1 files changed, 2 insertions, 19 deletions

diff --git a/virt/kvm/arm/vgic-v2-emul.c b/virt/kvm/arm/vgic-v2-emul.c
index 7460b376d090..13907970d11c 100644
--- a/virt/kvm/arm/vgic-v2-emul.c
+++ b/virt/kvm/arm/vgic-v2-emul.c
@@ -404,24 +404,6 @@ static const struct vgic_io_range vgic_dist_ranges[] = {
 	{}
 };
 
-static bool vgic_v2_handle_mmio(struct kvm_vcpu *vcpu, struct kvm_run *run,
-				struct kvm_exit_mmio *mmio)
-{
-	unsigned long base = vcpu->kvm->arch.vgic.vgic_dist_base;
-
-	if (!is_in_range(mmio->phys_addr, mmio->len, base,
-			 KVM_VGIC_V2_DIST_SIZE))
-		return false;
-
-	/* GICv2 does not support accesses wider than 32 bits */
-	if (mmio->len > 4) {
-		kvm_inject_dabt(vcpu, mmio->phys_addr);
-		return true;
-	}
-
-	return vgic_handle_mmio_range(vcpu, run, mmio, vgic_dist_ranges, base);
-}
-
 static void vgic_dispatch_sgi(struct kvm_vcpu *vcpu, u32 reg)
 {
 	struct kvm *kvm = vcpu->kvm;
@@ -580,7 +562,6 @@ void vgic_v2_init_emulation(struct kvm *kvm)
 {
 	struct vgic_dist *dist = &kvm->arch.vgic;
 
-	dist->vm_ops.handle_mmio = vgic_v2_handle_mmio;
 	dist->vm_ops.queue_sgi = vgic_v2_queue_sgi;
 	dist->vm_ops.add_sgi_source = vgic_v2_add_sgi_source;
 	dist->vm_ops.init_model = vgic_v2_init_model;
@@ -690,6 +671,7 @@ static int vgic_attr_regs_access(struct kvm_device *dev,
 	struct kvm_vcpu *vcpu, *tmp_vcpu;
 	struct vgic_dist *vgic;
 	struct kvm_exit_mmio mmio;
+	u32 data;
 
 	offset = attr->attr & KVM_DEV_ARM_VGIC_OFFSET_MASK;
 	cpuid = (attr->attr & KVM_DEV_ARM_VGIC_CPUID_MASK) >>
@@ -711,6 +693,7 @@ static int vgic_attr_regs_access(struct kvm_device *dev,
 
 	mmio.len = 4;
 	mmio.is_write = is_write;
+	mmio.data = &data;
 	if (is_write)
 		mmio_data_write(&mmio, ~0, *reg);
 	switch (attr->group) {