Thread (60 messages) 60 messages, 6 authors, 2016-04-26
STALE3734d

[PATCH 24/45] KVM: arm/arm64: vgic-new: Add GICv3 CTLR, IIDR, TYPER handlers

From: Peter Maydell <hidden>
Date: 2016-04-19 12:26:39
Also in: kvm, kvmarm

On 15 April 2016 at 18:11, Andre Przywara [off-list ref] wrote:
quoted hunk ↗ jump to hunk
As in the GICv2 emulation we handle those three registers in one
function.

Signed-off-by: Andre Przywara <andre.przywara@arm.com>

Changelog RFC..v1:
- kick VCPUs if distributor gets enabled
---
 virt/kvm/arm/vgic/vgic.h      |  2 ++
 virt/kvm/arm/vgic/vgic_mmio.c | 56 ++++++++++++++++++++++++++++++++++++++++++-
 2 files changed, 57 insertions(+), 1 deletion(-)
diff --git a/virt/kvm/arm/vgic/vgic.h b/virt/kvm/arm/vgic/vgic.h
index ccae13e..83b342c 100644
--- a/virt/kvm/arm/vgic/vgic.h
+++ b/virt/kvm/arm/vgic/vgic.h
@@ -19,6 +19,8 @@
 #define PRODUCT_ID_KVM         0x4b    /* ASCII code K */
 #define IMPLEMENTER_ARM                0x43b

+#define INTERRUPT_ID_BITS_SPIS 10
+
 #define vgic_irq_is_sgi(intid) ((intid) < VGIC_NR_SGIS)

 struct vgic_irq *vgic_get_irq(struct kvm *kvm, struct kvm_vcpu *vcpu,
diff --git a/virt/kvm/arm/vgic/vgic_mmio.c b/virt/kvm/arm/vgic/vgic_mmio.c
index 4a31d60..a87bbca 100644
--- a/virt/kvm/arm/vgic/vgic_mmio.c
+++ b/virt/kvm/arm/vgic/vgic_mmio.c
@@ -686,6 +686,60 @@ static int vgic_mmio_write_sgipends(struct kvm_vcpu *vcpu,
        return 0;
 }

+/*****************************/
+/* GICv3 emulation functions */
+/*****************************/
+#ifdef CONFIG_KVM_ARM_VGIC_V3
+
+static int vgic_mmio_read_v3_misc(struct kvm_vcpu *vcpu,
+                                 struct kvm_io_device *dev,
+                                 gpa_t addr, int len, void *val)
+{
+       u32 value = 0;
+
+       switch (addr & 0x0c) {
+       case GICD_CTLR:
+               if (vcpu->kvm->arch.vgic.enabled)
+                      value |= GICD_CTLR_ENABLE_SS_G1;
...what about the EnableGrp0 bit ? You're a single-security-State
GIC (since you advertise DS==1), so you should have two enable bits here.
+               value |= GICD_CTLR_ARE_NS | GICD_CTLR_DS;
+               break;
+       case GICD_TYPER:
+               value = vcpu->kvm->arch.vgic.nr_spis + VGIC_NR_PRIVATE_IRQS;
+               value = (value >> 5) - 1;
+               value |= (INTERRUPT_ID_BITS_SPIS - 1) << 19;
Are you deliberately claiming support for 1-of-N SPI interrupts (No1N == 0) ?
Is A3V==0 (no support for non-zero Aff3) correct? Is it a restriction we
might lift in future?
+               break;
+       case GICD_IIDR:
+               value = (PRODUCT_ID_KVM << 24) | (IMPLEMENTER_ARM << 0);
+               break;
+       default:
+               return 0;
+       }
+
+       write_mask32(value, addr & 3, len, val);
+       return 0;
+}
+
+static int vgic_mmio_write_v3_misc(struct kvm_vcpu *vcpu,
+                                  struct kvm_io_device *dev,
+                                  gpa_t addr, int len, const void *val)
+{
+       struct vgic_dist *dist = &vcpu->kvm->arch.vgic;
+       bool was_enabled = dist->enabled;
+
+       /* Of the whole region only the first byte is actually writeable. */
+       if ((addr & 0x0f) > 0)
+               return 0;
+
+       /* We only care about the enable bit, all other bits are WI. */
+       dist->enabled = *(u8*)val & GICD_CTLR_ENABLE_SS_G1;
Again, there are two enable bits here.

Also, this is a 32-bit register, so how does the *(u8*) work?
quoted hunk ↗ jump to hunk
+
+       if (!was_enabled && dist->enabled)
+               vgic_kick_vcpus(vcpu->kvm);
+
+       return 0;
+}
+
+
 /*
  * The GICv3 per-IRQ registers are split to control PPIs and SGIs in the
  * redistributors, while SPIs are covered by registers in the distributor
@@ -734,7 +788,7 @@ struct vgic_register_region vgic_v2_dist_registers[] = {
 #ifdef CONFIG_KVM_ARM_VGIC_V3
 struct vgic_register_region vgic_v3_dist_registers[] = {
        REGISTER_DESC_WITH_LENGTH(GICD_CTLR,
-               vgic_mmio_read_nyi, vgic_mmio_write_nyi, 16),
+               vgic_mmio_read_v3_misc, vgic_mmio_write_v3_misc, 16),
...and here it says 16, which is neither 8 nor 32...
        REGISTER_DESC_WITH_BITS_PER_IRQ_SHARED(GICD_IGROUPR,
                vgic_mmio_read_rao, vgic_mmio_write_wi, 1),
        REGISTER_DESC_WITH_BITS_PER_IRQ_SHARED(GICD_ISENABLER,
--
2.7.3
thanks
-- PMM
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