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[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] [Xen-devel] [RFC PATCH 12/24] ARM: vGICv3: introduce basic ITS emulation bits
Create a new file to hold the emulation code for the ITS widget.
For now we emulate the memory mapped ITS registers and provide a stub
to introduce the ITS command handling framework (but without actually
emulating any commands at this time).
Signed-off-by: Andre Przywara <andre.przywara@xxxxxxx>
---
xen/arch/arm/Makefile | 1 +
xen/arch/arm/vgic-its.c | 378 ++++++++++++++++++++++++++++++++++++++
xen/arch/arm/vgic-v3.c | 9 -
xen/include/asm-arm/gic_v3_defs.h | 19 ++
4 files changed, 398 insertions(+), 9 deletions(-)
create mode 100644 xen/arch/arm/vgic-its.c
diff --git a/xen/arch/arm/Makefile b/xen/arch/arm/Makefile
index c2c4daa..cb0201f 100644
--- a/xen/arch/arm/Makefile
+++ b/xen/arch/arm/Makefile
@@ -44,6 +44,7 @@ obj-y += traps.o
obj-y += vgic.o
obj-y += vgic-v2.o
obj-$(CONFIG_ARM_64) += vgic-v3.o
+obj-$(CONFIG_HAS_ITS) += vgic-its.o
obj-y += vm_event.o
obj-y += vtimer.o
obj-y += vpsci.o
diff --git a/xen/arch/arm/vgic-its.c b/xen/arch/arm/vgic-its.c
new file mode 100644
index 0000000..875b992
--- /dev/null
+++ b/xen/arch/arm/vgic-its.c
@@ -0,0 +1,378 @@
+/*
+ * xen/arch/arm/vgic-its.c
+ *
+ * ARM Interrupt Translation Service (ITS) emulation
+ *
+ * Andre Przywara <andre.przywara@xxxxxxx>
+ * Copyright (c) 2016 ARM Ltd.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ */
+
+#include <xen/bitops.h>
+#include <xen/config.h>
+#include <xen/domain_page.h>
+#include <xen/lib.h>
+#include <xen/init.h>
+#include <xen/softirq.h>
+#include <xen/irq.h>
+#include <xen/sched.h>
+#include <xen/sizes.h>
+#include <asm/current.h>
+#include <asm/mmio.h>
+#include <asm/gic_v3_defs.h>
+#include <asm/gic-its.h>
+#include <asm/vgic.h>
+#include <asm/vgic-emul.h>
+
+/* Data structure to describe a virtual ITS */
+struct virt_its {
+ struct domain *d;
+ struct host_its *hw_its;
+ spinlock_t vcmd_lock; /* protects the virtual command buffer */
+ uint64_t cbaser;
+ uint64_t *cmdbuf;
+ int cwriter;
+ int creadr;
+ spinlock_t its_lock; /* protects the collection and device tables */
+ uint64_t baser0, baser1;
+ uint16_t *coll_table;
+ int max_collections;
+ uint64_t *dev_table;
+ int max_devices;
+ bool enabled;
+};
+
+/* An Interrupt Translation Table Entry: this is indexed by a
+ * DeviceID/EventID pair and is located in guest memory.
+ */
+struct vits_itte
+{
+ uint64_t hlpi:24;
+ uint64_t vlpi:24;
+ uint64_t collection:16;
+};
+
+/**************************************
+ * Functions that handle ITS commands *
+ **************************************/
+
+static uint64_t its_cmd_mask_field(uint64_t *its_cmd,
+ int word, int shift, int size)
+{
+ return (le64_to_cpu(its_cmd[word]) >> shift) & (BIT(size) - 1);
+}
+
+#define its_cmd_get_command(cmd) its_cmd_mask_field(cmd, 0, 0, 8)
+#define its_cmd_get_deviceid(cmd) its_cmd_mask_field(cmd, 0, 32, 32)
+#define its_cmd_get_size(cmd) its_cmd_mask_field(cmd, 1, 0, 5)
+#define its_cmd_get_id(cmd) its_cmd_mask_field(cmd, 1, 0, 32)
+#define its_cmd_get_physical_id(cmd) its_cmd_mask_field(cmd, 1, 32, 32)
+#define its_cmd_get_collection(cmd) its_cmd_mask_field(cmd, 2, 0, 16)
+#define its_cmd_get_target_addr(cmd) its_cmd_mask_field(cmd, 2, 16, 32)
+#define its_cmd_get_validbit(cmd) its_cmd_mask_field(cmd, 2, 63, 1)
+
+#define ITS_CMD_BUFFER_SIZE(baser) ((((baser) & 0xff) + 1) << 12)
+
+static int vgic_its_handle_cmds(struct domain *d, struct virt_its *its,
+ uint32_t writer)
+{
+ uint64_t *cmdptr;
+
+ if ( !its->cmdbuf )
+ return -1;
+
+ if ( writer >= ITS_CMD_BUFFER_SIZE(its->cbaser) )
+ return -1;
+
+ spin_lock(&its->vcmd_lock);
+
+ while ( its->creadr != writer )
+ {
+ cmdptr = its->cmdbuf + (its->creadr / sizeof(*its->cmdbuf));
+ switch (its_cmd_get_command(cmdptr))
+ {
+ case GITS_CMD_SYNC:
+ /* We handle ITS commands synchronously, so we ignore SYNC. */
+ break;
+ default:
+ gdprintk(XENLOG_G_WARNING, "ITS: unhandled ITS command %ld\n",
+ its_cmd_get_command(cmdptr));
+ break;
+ }
+
+ its->creadr += ITS_CMD_SIZE;
+ if ( its->creadr == ITS_CMD_BUFFER_SIZE(its->cbaser) )
+ its->creadr = 0;
+ }
+ its->cwriter = writer;
+
+ spin_unlock(&its->vcmd_lock);
+
+ return 0;
+}
+
+/*****************************
+ * ITS registers read access *
+ *****************************/
+
+/* The physical address is encoded slightly differently depending on
+ * the used page size: the highest four bits are stored in the lowest
+ * four bits of the field for 64K pages.
+ */
+static paddr_t get_baser_phys_addr(uint64_t reg)
+{
+ if ( reg & BIT(9) )
+ return (reg & GENMASK(47, 16)) | ((reg & GENMASK(15, 12)) << 36);
+ else
+ return reg & GENMASK(47, 12);
+}
+
+static int vgic_v3_its_mmio_read(struct vcpu *v, mmio_info_t *info,
+ register_t *r, void *priv)
+{
+ struct virt_its *its = priv;
+
+ switch ( info->gpa & 0xffff )
+ {
+ case VREG32(GITS_CTLR):
+ if ( info->dabt.size != DABT_WORD ) goto bad_width;
+ *r = vgic_reg32_extract(its->enabled | BIT(31), info);
+ break;
+ case VREG32(GITS_IIDR):
+ if ( info->dabt.size != DABT_WORD ) goto bad_width;
+ *r = vgic_reg32_extract(GITS_IIDR_VALUE, info);
+ break;
+ case VREG64(GITS_TYPER):
+ if ( info->dabt.size < DABT_WORD ) goto bad_width;
+ *r = vgic_reg64_extract(0x1eff1, info);
+ break;
+ case VREG64(GITS_CBASER):
+ if ( info->dabt.size < DABT_WORD ) goto bad_width;
+ *r = vgic_reg64_extract(its->cbaser, info);
+ break;
+ case VREG64(GITS_CWRITER):
+ if ( info->dabt.size < DABT_WORD ) goto bad_width;
+ *r = vgic_reg64_extract(its->cwriter, info);
+ break;
+ case VREG64(GITS_CREADR):
+ if ( info->dabt.size < DABT_WORD ) goto bad_width;
+ *r = vgic_reg64_extract(its->creadr, info);
+ break;
+ case VREG64(GITS_BASER0):
+ if ( info->dabt.size < DABT_WORD ) goto bad_width;
+ *r = vgic_reg64_extract(its->baser0, info);
+ break;
+ case VREG64(GITS_BASER1):
+ if ( info->dabt.size < DABT_WORD ) goto bad_width;
+ *r = vgic_reg64_extract(its->baser1, info);
+ break;
+ case VRANGE64(GITS_BASER2, GITS_BASER7):
+ if ( info->dabt.size < DABT_WORD ) goto bad_width;
+ *r = vgic_reg64_extract(0, info);
+ break;
+ case VREG32(GICD_PIDR2):
+ if ( info->dabt.size != DABT_WORD ) goto bad_width;
+ *r = vgic_reg32_extract(GICV3_GICD_PIDR2, info);
+ break;
+ }
+
+ return 1;
+
+bad_width:
+ domain_crash_synchronous();
+
+ return 0;
+}
+
+/******************************
+ * ITS registers write access *
+ ******************************/
+
+static int its_baser_table_size(uint64_t baser)
+{
+ int page_size = 0;
+
+ switch ( (baser >> 8) & 3 )
+ {
+ case 0: page_size = SZ_4K; break;
+ case 1: page_size = SZ_16K; break;
+ case 2:
+ case 3: page_size = SZ_64K; break;
+ }
+
+ return page_size * ((baser & GENMASK(7, 0)) + 1);
+}
+
+static int its_baser_nr_entries(uint64_t baser)
+{
+ int entry_size = ((baser & GENMASK(52, 48)) >> 48) + 1;
+
+ return its_baser_table_size(baser) / entry_size;
+}
+
+static int vgic_v3_its_mmio_write(struct vcpu *v, mmio_info_t *info,
+ register_t r, void *priv)
+{
+ struct domain *d = v->domain;
+ struct virt_its *its = priv;
+ uint64_t reg;
+ uint32_t ctlr;
+
+ switch ( info->gpa & 0xffff )
+ {
+ case VREG32(GITS_CTLR):
+ ctlr = its->enabled ? GITS_CTLR_ENABLE : 0;
+ if ( info->dabt.size != DABT_WORD ) goto bad_width;
+ vgic_reg32_update(&ctlr, r, info);
+ its->enabled = ctlr & GITS_CTLR_ENABLE;
+ /* TODO: trigger something ... */
+ return 1;
+ case VREG32(GITS_IIDR):
+ goto write_ignore_32;
+ case VREG32(GITS_TYPER):
+ goto write_ignore_32;
+ case VREG64(GITS_CBASER):
+ if ( info->dabt.size < DABT_WORD ) goto bad_width;
+
+ /* Changing base registers with the ITS enabled is UNPREDICTABLE. */
+ if ( its->enabled )
+ return 1;
+
+ reg = its->cbaser;
+ vgic_reg64_update(®, r, info);
+ /* TODO: sanitise! */
+ its->cbaser = reg;
+
+ if ( reg & BIT(63) )
+ {
+ its->cmdbuf = map_guest_pages(d, reg & GENMASK(51, 12), 1);
+ }
+ else
+ {
+ unmap_guest_pages(its->cmdbuf, 1);
+ its->cmdbuf = NULL;
+ }
+
+ return 1;
+ case VREG64(GITS_CWRITER):
+ if ( info->dabt.size < DABT_WORD ) goto bad_width;
+ reg = its->cwriter;
+ vgic_reg64_update(®, r, info);
+ vgic_its_handle_cmds(d, its, reg);
+ return 1;
+ case VREG64(GITS_CREADR):
+ goto write_ignore_64;
+ case VREG64(GITS_BASER0):
+ if ( info->dabt.size < DABT_WORD ) goto bad_width;
+
+ /* Changing base registers with the ITS enabled is UNPREDICTABLE. */
+ if ( its->enabled )
+ return 1;
+
+ reg = its->baser0;
+ vgic_reg64_update(®, r, info);
+
+ reg &= ~GITS_BASER_RO_MASK;
+ reg |= (sizeof(uint64_t) - 1) << GITS_BASER_ENTRY_SIZE_SHIFT;
+ reg |= GITS_BASER_TYPE_DEVICE << GITS_BASER_TYPE_SHIFT;
+ /* TODO: sanitise! */
+ /* TODO: locking(?) */
+
+ if ( reg & GITS_BASER_VALID )
+ {
+ its->dev_table = map_guest_pages(d,
+ get_baser_phys_addr(reg),
+ its_baser_table_size(reg) >>
PAGE_SHIFT);
+ its->max_devices = its_baser_nr_entries(reg);
+ memset(its->dev_table, 0, its->max_devices * sizeof(uint64_t));
+ }
+ else
+ {
+ unmap_guest_pages(its->dev_table,
+ its_baser_table_size(reg) >> PAGE_SHIFT);
+ its->max_devices = 0;
+ }
+
+ its->baser0 = reg;
+ return 1;
+ case VREG64(GITS_BASER1):
+ if ( info->dabt.size < DABT_WORD ) goto bad_width;
+
+ /* Changing base registers with the ITS enabled is UNPREDICTABLE. */
+ if ( its->enabled )
+ return 1;
+
+ reg = its->baser1;
+ vgic_reg64_update(®, r, info);
+ reg &= ~GITS_BASER_RO_MASK;
+ reg |= (sizeof(uint16_t) - 1) << GITS_BASER_ENTRY_SIZE_SHIFT;
+ reg |= GITS_BASER_TYPE_COLLECTION << GITS_BASER_TYPE_SHIFT;
+ /* TODO: sanitise! */
+
+ /* TODO: sort out locking */
+ /* TODO: repeated calls: free old mapping */
+ if ( reg & GITS_BASER_VALID )
+ {
+ its->coll_table = map_guest_pages(d, get_baser_phys_addr(reg),
+ its_baser_table_size(reg) >>
PAGE_SHIFT);
+ its->max_collections = its_baser_nr_entries(reg);
+ memset(its->coll_table, 0xff,
+ its->max_collections * sizeof(uint16_t));
+ }
+ else
+ {
+ unmap_guest_pages(its->coll_table,
+ its_baser_table_size(reg) >> PAGE_SHIFT);
+ its->max_collections = 0;
+ }
+ its->baser1 = reg;
+ return 1;
+ case VRANGE64(GITS_BASER2, GITS_BASER7):
+ goto write_ignore_64;
+ default:
+ gdprintk(XENLOG_G_WARNING, "ITS: unhandled ITS register 0x%lx\n",
+ info->gpa & 0xffff);
+ return 0;
+ }
+
+ return 1;
+
+write_ignore_64:
+ if ( ! vgic_reg64_check_access(info->dabt) ) goto bad_width;
+ return 1;
+
+write_ignore_32:
+ if ( info->dabt.size != DABT_WORD ) goto bad_width;
+ return 1;
+
+bad_width:
+ printk(XENLOG_G_ERR "%pv vGICR: bad read width %d r%d offset %#08lx\n",
+ v, info->dabt.size, info->dabt.reg, info->gpa & 0xffff);
+
+ domain_crash_synchronous();
+
+ return 0;
+}
+
+static const struct mmio_handler_ops vgic_its_mmio_handler = {
+ .read = vgic_v3_its_mmio_read,
+ .write = vgic_v3_its_mmio_write,
+};
+
+/*
+ * Local variables:
+ * mode: C
+ * c-file-style: "BSD"
+ * c-basic-offset: 4
+ * indent-tabs-mode: nil
+ * End:
+ */
diff --git a/xen/arch/arm/vgic-v3.c b/xen/arch/arm/vgic-v3.c
index 8fe8386..aa53a1e 100644
--- a/xen/arch/arm/vgic-v3.c
+++ b/xen/arch/arm/vgic-v3.c
@@ -158,15 +158,6 @@ static void vgic_store_irouter(struct domain *d, struct
vgic_irq_rank *rank,
rank->vcpu[offset] = new_vcpu->vcpu_id;
}
-static inline bool vgic_reg64_check_access(struct hsr_dabt dabt)
-{
- /*
- * 64 bits registers can be accessible using 32-bit and 64-bit unless
- * stated otherwise (See 8.1.3 ARM IHI 0069A).
- */
- return ( dabt.size == DABT_DOUBLE_WORD || dabt.size == DABT_WORD );
-}
-
static int __vgic_v3_rdistr_rd_mmio_read(struct vcpu *v, mmio_info_t *info,
uint32_t gicr_reg,
register_t *r)
diff --git a/xen/include/asm-arm/gic_v3_defs.h
b/xen/include/asm-arm/gic_v3_defs.h
index da5fb77..6a91f5b 100644
--- a/xen/include/asm-arm/gic_v3_defs.h
+++ b/xen/include/asm-arm/gic_v3_defs.h
@@ -147,6 +147,16 @@
#define LPI_PROP_RES1 (1 << 1)
#define LPI_PROP_ENABLED (1 << 0)
+/*
+ * PIDR2: Only bits[7:4] are not implementation defined. We are
+ * emulating a GICv3 ([7:4] = 0x3).
+ *
+ * We don't emulate a specific registers scheme so implement the others
+ * bits as RES0 as recommended by the spec (see 8.1.13 in ARM IHI 0069A).
+ */
+#define GICV3_GICD_PIDR2 0x30
+#define GICV3_GICR_PIDR2 GICV3_GICD_PIDR2
+
#define GICH_VMCR_EOI (1 << 9)
#define GICH_VMCR_VENG1 (1 << 1)
@@ -190,6 +200,15 @@ struct rdist_region {
bool single_rdist;
};
+/*
+ * 64 bits registers can be accessible using 32-bit and 64-bit unless
+ * stated otherwise (See 8.1.3 ARM IHI 0069A).
+ */
+static inline bool vgic_reg64_check_access(struct hsr_dabt dabt)
+{
+ return ( dabt.size == DABT_DOUBLE_WORD || dabt.size == DABT_WORD );
+}
+
#endif /* __ASM_ARM_GIC_V3_DEFS_H__ */
/*
--
2.9.0
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