Add emulation for some basic MMIO registers used in the ITS emulation.
This includes:
- GITS_{CTLR,TYPER,IIDR}
- ID registers
- GITS_{CBASER,CREAD,CWRITER}
those implement the ITS command buffer handling
Signed-off-by: Andre Przywara <andre.przywara@xxxxxxx>
---
include/kvm/arm_vgic.h | 3 +
include/linux/irqchip/arm-gic-v3.h | 8 ++
virt/kvm/arm/its-emul.c | 172 +++++++++++++++++++++++++++++++++++++
virt/kvm/arm/its-emul.h | 1 +
virt/kvm/arm/vgic-v3-emul.c | 2 +
5 files changed, 186 insertions(+)
diff --git a/include/kvm/arm_vgic.h b/include/kvm/arm_vgic.h
index d76c2d9..3b8e3a1 100644
--- a/include/kvm/arm_vgic.h
+++ b/include/kvm/arm_vgic.h
@@ -159,6 +159,9 @@ struct vgic_io_device {
struct vgic_its {
bool enabled;
spinlock_t lock;
+ u64 cbaser;
+ int creadr;
+ int cwriter;
};
struct vgic_dist {
diff --git a/include/linux/irqchip/arm-gic-v3.h b/include/linux/irqchip/arm-gic-v3.h
index df4e527..0b450c7 100644
--- a/include/linux/irqchip/arm-gic-v3.h
+++ b/include/linux/irqchip/arm-gic-v3.h
@@ -179,15 +179,23 @@
#define GITS_BASER 0x0100
#define GITS_IDREGS_BASE 0xffd0
#define GITS_PIDR2 GICR_PIDR2
+#define GITS_PIDR4 0xffd0
+#define GITS_CIDR0 0xfff0
+#define GITS_CIDR1 0xfff4
+#define GITS_CIDR2 0xfff8
+#define GITS_CIDR3 0xfffc
#define GITS_TRANSLATER 0x10040
#define GITS_CTLR_ENABLE (1U << 0)
#define GITS_CTLR_QUIESCENT (1U << 31)
+#define GITS_TYPER_PLPIS (1UL << 0)
+#define GITS_TYPER_IDBITS_SHIFT 8
#define GITS_TYPER_DEVBITS_SHIFT 13
#define GITS_TYPER_DEVBITS(r) ((((r) >> GITS_TYPER_DEVBITS_SHIFT) & 0x1f) + 1)
#define GITS_TYPER_PTA (1UL << 19)
+#define GITS_TYPER_HWCOLLCNT_SHIFT 24
#define GITS_CBASER_VALID (1UL << 63)
#define GITS_CBASER_nCnB (0UL << 59)
diff --git a/virt/kvm/arm/its-emul.c b/virt/kvm/arm/its-emul.c
index 7b283ce..82bc34a 100644
--- a/virt/kvm/arm/its-emul.c
+++ b/virt/kvm/arm/its-emul.c
@@ -32,10 +32,62 @@
#include "vgic.h"
#include "its-emul.h"
+#define BASER_BASE_ADDRESS(x) ((x) & 0xfffffffff000ULL)
+
+/* distributor lock is hold by the VGIC MMIO handler */
static bool handle_mmio_misc_gits(struct kvm_vcpu *vcpu,
struct kvm_exit_mmio *mmio,
phys_addr_t offset)
{
+ struct vgic_its *its = &vcpu->kvm->arch.vgic.its;
+ u32 reg;
+ bool was_enabled;
+
+ switch (offset & ~3) {
+ case 0x00: /* GITS_CTLR */
+ /* We never defer any command execution. */
+ reg = GITS_CTLR_QUIESCENT;
+ if (its->enabled)
+ reg |= GITS_CTLR_ENABLE;
+ was_enabled = its->enabled;
+ vgic_reg_access(mmio, ®, offset & 3,
+ ACCESS_READ_VALUE | ACCESS_WRITE_VALUE);
+ its->enabled = !!(reg & GITS_CTLR_ENABLE);
+ return !was_enabled && its->enabled;
+ case 0x04: /* GITS_IIDR */
+ reg = (PRODUCT_ID_KVM << 24) | (IMPLEMENTER_ARM << 0);
+ vgic_reg_access(mmio, ®, offset & 3,
+ ACCESS_READ_VALUE | ACCESS_WRITE_IGNORED);
+ break;
+ case 0x08: /* GITS_TYPER */
+ /*
+ * We use linear CPU numbers for redistributor addressing,
+ * so GITS_TYPER.PTA is 0.
+ * To avoid memory waste on the guest side, we keep the
+ * number of IDBits and DevBits low for the time being.
+ * This could later be made configurable by userland.
+ * Since we have all collections in linked list, we claim
+ * that we can hold all of the collection tables in our
+ * own memory and that the ITT entry size is 1 byte (the
+ * smallest possible one).
+ */
+ reg = GITS_TYPER_PLPIS;
+ reg |= 0xff << GITS_TYPER_HWCOLLCNT_SHIFT;
+ reg |= 0x0f << GITS_TYPER_DEVBITS_SHIFT;
+ reg |= 0x0f << GITS_TYPER_IDBITS_SHIFT;
+ vgic_reg_access(mmio, ®, offset & 3,
+ ACCESS_READ_VALUE | ACCESS_WRITE_IGNORED);
+ break;
+ case 0x0c:
+ /* The upper 32bits of TYPER are all 0 for the time being.
+ * Should we need more than 256 collections, we can enable
+ * some bits in here.
+ */
+ vgic_reg_access(mmio, NULL, offset & 3,
+ ACCESS_READ_RAZ | ACCESS_WRITE_IGNORED);
+ break;
+ }
+
return false;
}
@@ -43,20 +95,107 @@ static bool handle_mmio_gits_idregs(struct kvm_vcpu *vcpu,
struct kvm_exit_mmio *mmio,
phys_addr_t offset)
{
+ u32 reg = 0;
+ int idreg = (offset & ~3) + GITS_IDREGS_BASE;
+
+ switch (idreg) {
+ case GITS_PIDR2:
+ reg = GIC_PIDR2_ARCH_GICv3;
+ break;
+ case GITS_PIDR4:
+ /* This is a 64K software visible page */
+ reg = 0x40;
+ break;
+ /* Those are the ID registers for (any) GIC. */
+ case GITS_CIDR0:
+ reg = 0x0d;
+ break;
+ case GITS_CIDR1:
+ reg = 0xf0;
+ break;
+ case GITS_CIDR2:
+ reg = 0x05;
+ break;
+ case GITS_CIDR3:
+ reg = 0xb1;
+ break;
+ }
+ vgic_reg_access(mmio, ®, offset & 3,
+ ACCESS_READ_VALUE | ACCESS_WRITE_IGNORED);
return false;
}
+static int vits_handle_command(struct kvm_vcpu *vcpu, u64 *its_cmd)
+{
+ return -ENODEV;
+}
+
static bool handle_mmio_gits_cbaser(struct kvm_vcpu *vcpu,
struct kvm_exit_mmio *mmio,
phys_addr_t offset)
{
+ struct vgic_its *its = &vcpu->kvm->arch.vgic.its;
+ int mode = ACCESS_READ_VALUE;
+
+ mode |= its->enabled ? ACCESS_WRITE_IGNORED : ACCESS_WRITE_VALUE;
+
+ vgic_handle_base_register(vcpu, mmio, offset, &its->cbaser, mode);
+ if (mmio->is_write)
+ its->creadr = 0;
return false;
}
+static int its_cmd_buffer_size(struct kvm *kvm)
+{
+ struct vgic_its *its = &kvm->arch.vgic.its;
+
+ return ((its->cbaser & 0xff) + 1) << 12;
+}
+
+static gpa_t its_cmd_buffer_base(struct kvm *kvm)
+{
+ struct vgic_its *its = &kvm->arch.vgic.its;
+
+ return BASER_BASE_ADDRESS(its->cbaser);
+}
+
static bool handle_mmio_gits_cwriter(struct kvm_vcpu *vcpu,
struct kvm_exit_mmio *mmio,
phys_addr_t offset)
{
+ struct vgic_its *its = &vcpu->kvm->arch.vgic.its;
+ u64 cmd_buf[4];
+ gpa_t cbaser = its_cmd_buffer_base(vcpu->kvm);
+ u32 reg;
+ int ret;
+
+ spin_lock(&its->lock);
+ switch (offset & ~3) {
+ case 0x00:
+ reg = its->cwriter & 0xfffe0;
+ vgic_reg_access(mmio, ®, offset & 3,
+ ACCESS_READ_VALUE | ACCESS_WRITE_VALUE);
+ reg &= 0xfffe0;
+ if (reg > its_cmd_buffer_size(vcpu->kvm))
+ break;
+ while (its->creadr != reg) {
+ ret = kvm_read_guest(vcpu->kvm, cbaser + its->creadr,
+ cmd_buf, 32);
+ if (ret)
+ break;
+ vits_handle_command(vcpu, cmd_buf);
+ its->creadr += 32;
+ if (its->creadr == its_cmd_buffer_size(vcpu->kvm))
+ its->creadr = 0;
+ }
+ its->cwriter = reg;
+ break;
+ case 0x04:
+ vgic_reg_access(mmio, ®, offset & 3,
+ ACCESS_READ_RAZ | ACCESS_WRITE_IGNORED);
+ break;
+ }
+ spin_unlock(&its->lock);
return false;
}
@@ -64,6 +203,22 @@ static bool handle_mmio_gits_creadr(struct kvm_vcpu *vcpu,
struct kvm_exit_mmio *mmio,
phys_addr_t offset)
{
+ struct vgic_its *its = &vcpu->kvm->arch.vgic.its;
+ u32 reg;
+
+ spin_lock(&its->lock);
+ switch (offset & ~3) {
+ case 0x00:
+ reg = its->creadr & 0xfffe0;
+ vgic_reg_access(mmio, ®, offset & 3,
+ ACCESS_READ_VALUE | ACCESS_WRITE_IGNORED);
+ break;
+ case 0x04:
+ vgic_reg_access(mmio, ®, offset & 3,
+ ACCESS_READ_RAZ | ACCESS_WRITE_IGNORED);
+ break;
+ }
+ spin_unlock(&its->lock);
return false;
}
@@ -119,9 +274,26 @@ int vits_init(struct kvm *kvm)
if (IS_VGIC_ADDR_UNDEF(dist->vgic_its_base))
return -ENXIO;
+ dist->pendbaser = kmalloc(sizeof(u64) * dist->nr_cpus, GFP_KERNEL);
+ if (!dist->pendbaser)
+ return -ENOMEM;
+
spin_lock_init(&its->lock);
its->enabled = false;
return -ENXIO;
}
+
+void vits_destroy(struct kvm *kvm)
+{
+ struct vgic_dist *dist = &kvm->arch.vgic;
+ struct vgic_its *its = &dist->its;
+
+ if (!vgic_has_its(kvm))
+ return;
+
+ kfree(dist->pendbaser);
+
+ its->enabled = false;
+}
diff --git a/virt/kvm/arm/its-emul.h b/virt/kvm/arm/its-emul.h
index 5dc8e2f..472a6d0 100644
--- a/virt/kvm/arm/its-emul.h
+++ b/virt/kvm/arm/its-emul.h
@@ -31,5 +31,6 @@
void vgic_enable_lpis(struct kvm_vcpu *vcpu);
int vits_init(struct kvm *kvm);
+void vits_destroy(struct kvm *kvm);
#endif
diff --git a/virt/kvm/arm/vgic-v3-emul.c b/virt/kvm/arm/vgic-v3-emul.c
index 4e40684..fa81c4b 100644
--- a/virt/kvm/arm/vgic-v3-emul.c
+++ b/virt/kvm/arm/vgic-v3-emul.c
@@ -881,6 +881,8 @@ static void vgic_v3_destroy_model(struct kvm *kvm)
{
struct vgic_dist *dist = &kvm->arch.vgic;
+ vits_destroy(kvm);
+
kfree(dist->irq_spi_mpidr);
dist->irq_spi_mpidr = NULL;
}
--
2.3.5
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