arm/arm64: KVM: add virtual GICv3 distributor emulation

With everything separated and prepared, we implement a model of a
GICv3 distributor and redistributors by using the existing framework
to provide handler functions for each register group.

Currently we limit the emulation to a model enforcing a single
security state, with SRE==1 (forcing system register access) and
ARE==1 (allowing more than 8 VCPUs).

We share some of the functions provided for GICv2 emulation, but take
the different ways of addressing (v)CPUs into account.
Save and restore is currently not implemented.

Similar to the split-off of the GICv2 specific code, the new emulation
code goes into a new file (vgic-v3-emul.c).

Signed-off-by: Andre Przywara <andre.przywara@arm.com>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>

4 files changed, 43 insertions, 1 deletions

diff --git a/include/kvm/arm_vgic.h b/include/kvm/arm_vgic.h
index ff04afd0d901..98c30168bce4 100644
--- a/include/kvm/arm_vgic.h
+++ b/include/kvm/arm_vgic.h
@@ -162,7 +162,11 @@ struct vgic_dist {
 
         /* Distributor and vcpu interface mapping in the guest */
         phys_addr_t             vgic_dist_base;
-        phys_addr_t             vgic_cpu_base;
+        /* GICv2 and GICv3 use different mapped register blocks */
+        union {
+                phys_addr_t             vgic_cpu_base;
+                phys_addr_t             vgic_redist_base;
+        };
 
         /* Distributor enabled */
         u32                     enabled;
@@ -224,6 +228,9 @@ struct vgic_dist {
          */
         struct vgic_bitmap      *irq_spi_target;
 
+        /* Target MPIDR for each IRQ (needed for GICv3 IROUTERn) only */
+        u32                     *irq_spi_mpidr;
+
         /* Bitmap indicating which CPU has something pending */
         unsigned long           *irq_pending_on_cpu;
 
diff --git a/include/linux/irqchip/arm-gic-v3.h b/include/linux/irqchip/arm-gic-v3.h
index 1e8b0cf30792..3fb4d8588a26 100644
--- a/include/linux/irqchip/arm-gic-v3.h
+++ b/include/linux/irqchip/arm-gic-v3.h
@@ -33,6 +33,7 @@
 #define GICD_SETSPI_SR                  0x0050
 #define GICD_CLRSPI_SR                  0x0058
 #define GICD_SEIR                       0x0068
+#define GICD_IGROUPR                    0x0080
 #define GICD_ISENABLER                  0x0100
 #define GICD_ICENABLER                  0x0180
 #define GICD_ISPENDR                    0x0200
@@ -41,14 +42,37 @@
 #define GICD_ICACTIVER                  0x0380
 #define GICD_IPRIORITYR                 0x0400
 #define GICD_ICFGR                      0x0C00
+#define GICD_IGRPMODR                   0x0D00
+#define GICD_NSACR                      0x0E00
 #define GICD_IROUTER                    0x6000
+#define GICD_IDREGS                     0xFFD0
 #define GICD_PIDR2                      0xFFE8
 
+/*
+ * Those registers are actually from GICv2, but the spec demands that they
+ * are implemented as RES0 if ARE is 1 (which we do in KVM's emulated GICv3).
+ */
+#define GICD_ITARGETSR                  0x0800
+#define GICD_SGIR                       0x0F00
+#define GICD_CPENDSGIR                  0x0F10
+#define GICD_SPENDSGIR                  0x0F20
+
 #define GICD_CTLR_RWP                   (1U << 31)
+#define GICD_CTLR_DS                    (1U << 6)
 #define GICD_CTLR_ARE_NS                (1U << 4)
 #define GICD_CTLR_ENABLE_G1A            (1U << 1)
 #define GICD_CTLR_ENABLE_G1             (1U << 0)
 
+/*
+ * In systems with a single security state (what we emulate in KVM)
+ * the meaning of the interrupt group enable bits is slightly different
+ */
+#define GICD_CTLR_ENABLE_SS_G1          (1U << 1)
+#define GICD_CTLR_ENABLE_SS_G0          (1U << 0)
+
+#define GICD_TYPER_LPIS                 (1U << 17)
+#define GICD_TYPER_MBIS                 (1U << 16)
+
 #define GICD_TYPER_ID_BITS(typer)       ((((typer) >> 19) & 0x1f) + 1)
 #define GICD_TYPER_IRQS(typer)          ((((typer) & 0x1f) + 1) * 32)
 #define GICD_TYPER_LPIS                 (1U << 17)
@@ -60,6 +84,8 @@
 #define GIC_PIDR2_ARCH_GICv3            0x30
 #define GIC_PIDR2_ARCH_GICv4            0x40
 
+#define GIC_V3_DIST_SIZE                0x10000
+
 /*
  * Re-Distributor registers, offsets from RD_base
  */
@@ -78,6 +104,7 @@
 #define GICR_SYNCR                      0x00C0
 #define GICR_MOVLPIR                    0x0100
 #define GICR_MOVALLR                    0x0110
+#define GICR_IDREGS                     GICD_IDREGS
 #define GICR_PIDR2                      GICD_PIDR2
 
 #define GICR_CTLR_ENABLE_LPIS           (1UL << 0)
@@ -104,6 +131,7 @@
 /*
  * Re-Distributor registers, offsets from SGI_base
  */
+#define GICR_IGROUPR0                   GICD_IGROUPR
 #define GICR_ISENABLER0                 GICD_ISENABLER
 #define GICR_ICENABLER0                 GICD_ICENABLER
 #define GICR_ISPENDR0                   GICD_ISPENDR
@@ -112,11 +140,15 @@
 #define GICR_ICACTIVER0                 GICD_ICACTIVER
 #define GICR_IPRIORITYR0                GICD_IPRIORITYR
 #define GICR_ICFGR0                     GICD_ICFGR
+#define GICR_IGRPMODR0                  GICD_IGRPMODR
+#define GICR_NSACR                      GICD_NSACR
 
 #define GICR_TYPER_PLPIS                (1U << 0)
 #define GICR_TYPER_VLPIS                (1U << 1)
 #define GICR_TYPER_LAST                 (1U << 4)
 
+#define GIC_V3_REDIST_SIZE              0x20000
+
 #define LPI_PROP_GROUP1                 (1 << 1)
 #define LPI_PROP_ENABLED                (1 << 0)
 
diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h
index 25d7ce31a5d4..0ef2daa199d8 100644
--- a/include/linux/kvm_host.h
+++ b/include/linux/kvm_host.h
@@ -1052,6 +1052,7 @@ void kvm_unregister_device_ops(u32 type);
 extern struct kvm_device_ops kvm_mpic_ops;
 extern struct kvm_device_ops kvm_xics_ops;
 extern struct kvm_device_ops kvm_arm_vgic_v2_ops;
+extern struct kvm_device_ops kvm_arm_vgic_v3_ops;
 
 #ifdef CONFIG_HAVE_KVM_CPU_RELAX_INTERCEPT
 
diff --git a/include/uapi/linux/kvm.h b/include/uapi/linux/kvm.h
index a37fd1224f36..b4e6f1e70f03 100644
--- a/include/uapi/linux/kvm.h
+++ b/include/uapi/linux/kvm.h
@@ -952,6 +952,8 @@ enum kvm_device_type {
 #define KVM_DEV_TYPE_ARM_VGIC_V2        KVM_DEV_TYPE_ARM_VGIC_V2
         KVM_DEV_TYPE_FLIC,
 #define KVM_DEV_TYPE_FLIC               KVM_DEV_TYPE_FLIC
+        KVM_DEV_TYPE_ARM_VGIC_V3,
+#define KVM_DEV_TYPE_ARM_VGIC_V3        KVM_DEV_TYPE_ARM_VGIC_V3
         KVM_DEV_TYPE_MAX,
 };