diff mbox series

[Xen-devel,v2,24/45] ARM: new VGIC: Add CTLR, TYPER and IIDR handlers

Message ID 20180315203050.19791-25-andre.przywara@linaro.org
State Superseded
Headers show
Series New VGIC(-v2) implementation | expand

Commit Message

Andre Przywara March 15, 2018, 8:30 p.m. UTC
Those three registers are v2 emulation specific, so their implementation
lives entirely in vgic-mmio-v2.c. Also they are handled in one function,
as their implementation is pretty simple.
We choose to piggy-back on the existing KVM identification registers,
but use a different variant (major revision).
When the guest enables the distributor, we kick all VCPUs to get
potentially pending interrupts serviced.

This is based on Linux commit 2b0cda878965, written by Marc Zyngier.

Signed-off-by: Andre Przywara <andre.przywara@linaro.org>
---
Changelog v1 ... v2:
- use new IIDR values (KVM product ID, Xen revision)
- add comment on handling GICD enablement
- use new vcpu_kick() function

 xen/arch/arm/vgic/vgic-mmio-v2.c | 63 +++++++++++++++++++++++++++++++++++++++-
 xen/arch/arm/vgic/vgic.c         | 15 ++++++++++
 xen/arch/arm/vgic/vgic.h         |  5 ++++
 3 files changed, 82 insertions(+), 1 deletion(-)

Comments

Julien Grall March 19, 2018, 8:13 a.m. UTC | #1
Hi Andre,

On 03/15/2018 08:30 PM, Andre Przywara wrote:
> diff --git a/xen/arch/arm/vgic/vgic.h b/xen/arch/arm/vgic/vgic.h
> index 7f221fd195..e2d0f04440 100644
> --- a/xen/arch/arm/vgic/vgic.h
> +++ b/xen/arch/arm/vgic/vgic.h
> @@ -17,6 +17,10 @@
>   #ifndef __XEN_ARM_VGIC_VGIC_H__
>   #define __XEN_ARM_VGIC_VGIC_H__
>   
> +#define PRODUCT_ID_KVM          0x4b        /* ASCII code X */

I think you mean 'ASCII code K'.

Also, do you want to copy the commit message about the identifier in the 
code?

> +#define VARIANT_ID_XEN          0x01
> +#define IMPLEMENTER_ARM         0x43b
> +
>   #define vgic_irq_is_sgi(intid) ((intid) < VGIC_NR_SGIS)
>   
>   static inline bool irq_is_pending(struct vgic_irq *irq)
> @@ -37,6 +41,7 @@ struct vgic_irq *vgic_get_irq(struct domain *d, struct vcpu *vcpu,
>   void vgic_put_irq(struct domain *d, struct vgic_irq *irq);
>   void vgic_queue_irq_unlock(struct domain *d, struct vgic_irq *irq,
>                              unsigned long flags);
> +void vgic_kick_vcpus(struct domain *d);
>   
>   static inline void vgic_get_irq_kref(struct vgic_irq *irq)
>   {
> 

Cheers,
diff mbox series

Patch

diff --git a/xen/arch/arm/vgic/vgic-mmio-v2.c b/xen/arch/arm/vgic/vgic-mmio-v2.c
index 6f10cf16ca..43c1ab5906 100644
--- a/xen/arch/arm/vgic/vgic-mmio-v2.c
+++ b/xen/arch/arm/vgic/vgic-mmio-v2.c
@@ -20,9 +20,70 @@ 
 #include "vgic.h"
 #include "vgic-mmio.h"
 
+static unsigned long vgic_mmio_read_v2_misc(struct vcpu *vcpu,
+                                            paddr_t addr, unsigned int len)
+{
+    uint32_t value;
+
+    switch ( addr & 0x0c )      /* filter for the 4 registers handled here */
+    {
+    case GICD_CTLR:
+        value = vcpu->domain->arch.vgic.enabled ? GICD_CTL_ENABLE : 0;
+        break;
+    case GICD_TYPER:
+        value = vcpu->domain->arch.vgic.nr_spis + VGIC_NR_PRIVATE_IRQS;
+        value = (value >> 5) - 1;
+        value |= (vcpu->domain->max_vcpus - 1) << 5;
+        break;
+    case GICD_IIDR:
+        value = (PRODUCT_ID_KVM << 24) |
+                (VARIANT_ID_XEN << 16) |
+                (IMPLEMENTER_ARM << 0);
+        break;
+    default:
+        return 0;
+    }
+
+    return value;
+}
+
+static void vgic_mmio_write_v2_misc(struct vcpu *vcpu,
+                                    paddr_t addr, unsigned int len,
+                                    unsigned long val)
+{
+    struct vgic_dist *dist = &vcpu->domain->arch.vgic;
+    bool enabled;
+
+    switch ( addr & 0x0c )      /* filter for the 4 registers handled here */
+    {
+    case GICD_CTLR:
+        domain_lock(vcpu->domain);
+
+        /*
+         * Store the new enabled state in our distributor structure.
+         * Work out whether it was disabled before and now got enabled,
+         * so that we signal all VCPUs to check for interrupts to be injected.
+         */
+        enabled = dist->enabled;
+        dist->enabled = val & GICD_CTL_ENABLE;
+        enabled = !enabled && dist->enabled;
+
+        domain_unlock(vcpu->domain);
+
+        if ( enabled )
+            vgic_kick_vcpus(vcpu->domain);
+
+        break;
+    case GICD_TYPER:
+    case GICD_IIDR:
+        /* read-only, writes ignored */
+        return;
+    }
+}
+
 static const struct vgic_register_region vgic_v2_dist_registers[] = {
     REGISTER_DESC_WITH_LENGTH(GICD_CTLR,
-        vgic_mmio_read_raz, vgic_mmio_write_wi, 12,
+        vgic_mmio_read_v2_misc, vgic_mmio_write_v2_misc, 12,
         VGIC_ACCESS_32bit),
     REGISTER_DESC_WITH_BITS_PER_IRQ(GICD_IGROUPR,
         vgic_mmio_read_rao, vgic_mmio_write_wi, 1,
diff --git a/xen/arch/arm/vgic/vgic.c b/xen/arch/arm/vgic/vgic.c
index a1556e53e8..a3aaf20a73 100644
--- a/xen/arch/arm/vgic/vgic.c
+++ b/xen/arch/arm/vgic/vgic.c
@@ -674,6 +674,21 @@  int vgic_vcpu_pending_irq(struct vcpu *vcpu)
     return pending;
 }
 
+void vgic_kick_vcpus(struct domain *d)
+{
+    struct vcpu *vcpu;
+
+    /*
+     * We've injected an interrupt, time to find out who deserves
+     * a good kick...
+     */
+    for_each_vcpu( d, vcpu )
+    {
+        if ( vgic_vcpu_pending_irq(vcpu) )
+            vcpu_kick(vcpu);
+    }
+}
+
 /*
  * Local variables:
  * mode: C
diff --git a/xen/arch/arm/vgic/vgic.h b/xen/arch/arm/vgic/vgic.h
index 7f221fd195..e2d0f04440 100644
--- a/xen/arch/arm/vgic/vgic.h
+++ b/xen/arch/arm/vgic/vgic.h
@@ -17,6 +17,10 @@ 
 #ifndef __XEN_ARM_VGIC_VGIC_H__
 #define __XEN_ARM_VGIC_VGIC_H__
 
+#define PRODUCT_ID_KVM          0x4b        /* ASCII code X */
+#define VARIANT_ID_XEN          0x01
+#define IMPLEMENTER_ARM         0x43b
+
 #define vgic_irq_is_sgi(intid) ((intid) < VGIC_NR_SGIS)
 
 static inline bool irq_is_pending(struct vgic_irq *irq)
@@ -37,6 +41,7 @@  struct vgic_irq *vgic_get_irq(struct domain *d, struct vcpu *vcpu,
 void vgic_put_irq(struct domain *d, struct vgic_irq *irq);
 void vgic_queue_irq_unlock(struct domain *d, struct vgic_irq *irq,
                            unsigned long flags);
+void vgic_kick_vcpus(struct domain *d);
 
 static inline void vgic_get_irq_kref(struct vgic_irq *irq)
 {