Re: [PATCH 11/12] KVM: ARM: on IO mem abort - route the call to KVM MMIO bus

[Christoffer Dall]

On Fri, Mar 13, 2015 at 04:10:11PM +, Andre Przywara wrote:
 From: Nikolay Nikolaev n.nikol...@virtualopensystems.com
 
 On IO memory abort, try to handle the MMIO access through the KVM
 registered read/write callbacks. This is done by invoking the relevant
 kvm_io_bus_* API.
 
 [Andre: Since we converted the VGIC already, we can get rid of the
 VGIC specific MMIO handler alltogether.]
 
 Signed-off-by: Nikolay Nikolaev n.nikol...@virtualopensystems.com
 Signed-off-by: Andre Przywara andre.przyw...@arm.com
 ---
  arch/arm/kvm/mmio.c|   32 +++-
  include/kvm/arm_vgic.h |2 --
  2 files changed, 31 insertions(+), 3 deletions(-)
 
 diff --git a/arch/arm/kvm/mmio.c b/arch/arm/kvm/mmio.c
 index 5d3bfc0..8dc2fde 100644
 --- a/arch/arm/kvm/mmio.c
 +++ b/arch/arm/kvm/mmio.c
 @@ -162,6 +162,36 @@ static int decode_hsr(struct kvm_vcpu *vcpu, phys_addr_t 
 fault_ipa,
   return 0;
  }
  
 +/**
 + * handle_kernel_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_MMIO_BUS, mmio-phys_addr,
 + mmio-len, mmio-data);
 +
 + } else {
 + ret = kvm_io_bus_read(vcpu, KVM_MMIO_BUS, mmio-phys_addr,
 + mmio-len, mmio-data);
 + }
 + if (!ret) {
 + kvm_prepare_mmio(run, mmio);
 + kvm_handle_mmio_return(vcpu, run);

here I think you can optimize the copying, see my comment on the earlier
patch.

let's be nice to readers here and

return true

 + }
 +
 + return !ret;

and replace this with

return false

 +}
 +
  int io_mem_abort(struct kvm_vcpu *vcpu, struct kvm_run *run,
phys_addr_t fault_ipa)
  {
 @@ -200,7 +230,7 @@ int io_mem_abort(struct kvm_vcpu *vcpu, struct kvm_run 
 *run,
  fault_ipa, 0);
   }
  
 - if (vgic_handle_mmio(vcpu, run, mmio))
 + if (handle_kernel_mmio(vcpu, run, mmio))
   return 1;
  
   kvm_prepare_mmio(run, mmio);
 diff --git a/include/kvm/arm_vgic.h b/include/kvm/arm_vgic.h
 index 09fd324..91976c8 100644
 --- a/include/kvm/arm_vgic.h
 +++ b/include/kvm/arm_vgic.h
 @@ -317,8 +317,6 @@ int kvm_vgic_inject_irq(struct kvm *kvm, int cpuid, 
 unsigned int irq_num,
   bool level);
  void vgic_v3_dispatch_sgi(struct kvm_vcpu *vcpu, u64 reg);
  int kvm_vgic_vcpu_pending_irq(struct kvm_vcpu *vcpu);
 -bool vgic_handle_mmio(struct kvm_vcpu *vcpu, struct kvm_run *run,
 -   struct kvm_exit_mmio *mmio);
  
  #define irqchip_in_kernel(k) (!!((k)-arch.vgic.in_kernel))
  #define vgic_initialized(k)  (!!((k)-arch.vgic.nr_cpus))
 -- 
 1.7.9.5
 

Thanks,
-Christoffer
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[PATCH 11/12] KVM: ARM: on IO mem abort - route the call to KVM MMIO bus

[Andre Przywara]

From: Nikolay Nikolaev n.nikol...@virtualopensystems.com

On IO memory abort, try to handle the MMIO access through the KVM
registered read/write callbacks. This is done by invoking the relevant
kvm_io_bus_* API.

[Andre: Since we converted the VGIC already, we can get rid of the
VGIC specific MMIO handler alltogether.]

Signed-off-by: Nikolay Nikolaev n.nikol...@virtualopensystems.com
Signed-off-by: Andre Przywara andre.przyw...@arm.com
---
 arch/arm/kvm/mmio.c|   32 +++-
 include/kvm/arm_vgic.h |2 --
 2 files changed, 31 insertions(+), 3 deletions(-)

diff --git a/arch/arm/kvm/mmio.c b/arch/arm/kvm/mmio.c
index 5d3bfc0..8dc2fde 100644
--- a/arch/arm/kvm/mmio.c
+++ b/arch/arm/kvm/mmio.c
@@ -162,6 +162,36 @@ static int decode_hsr(struct kvm_vcpu *vcpu, phys_addr_t 
fault_ipa,
return 0;
 }
 
+/**
+ * handle_kernel_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_MMIO_BUS, mmio-phys_addr,
+   mmio-len, mmio-data);
+
+   } else {
+   ret = kvm_io_bus_read(vcpu, 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)
 {
@@ -200,7 +230,7 @@ int io_mem_abort(struct kvm_vcpu *vcpu, struct kvm_run *run,
   fault_ipa, 0);
}
 
-   if (vgic_handle_mmio(vcpu, run, mmio))
+   if (handle_kernel_mmio(vcpu, run, mmio))
return 1;
 
kvm_prepare_mmio(run, mmio);
diff --git a/include/kvm/arm_vgic.h b/include/kvm/arm_vgic.h
index 09fd324..91976c8 100644
--- a/include/kvm/arm_vgic.h
+++ b/include/kvm/arm_vgic.h
@@ -317,8 +317,6 @@ int kvm_vgic_inject_irq(struct kvm *kvm, int cpuid, 
unsigned int irq_num,
bool level);
 void vgic_v3_dispatch_sgi(struct kvm_vcpu *vcpu, u64 reg);
 int kvm_vgic_vcpu_pending_irq(struct kvm_vcpu *vcpu);
-bool vgic_handle_mmio(struct kvm_vcpu *vcpu, struct kvm_run *run,
- struct kvm_exit_mmio *mmio);
 
 #define irqchip_in_kernel(k)   (!!((k)-arch.vgic.in_kernel))
 #define vgic_initialized(k)(!!((k)-arch.vgic.nr_cpus))
-- 
1.7.9.5

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