[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

[xen staging] libxl: Introduce basic virtio-mmio support on Arm



commit 2128143c114c52c7536e37c32935fdd77f23edc1
Author:     Julien Grall <julien.grall@xxxxxxx>
AuthorDate: Fri Jul 15 22:20:25 2022 +0300
Commit:     Julien Grall <jgrall@xxxxxxxxxx>
CommitDate: Thu Jul 28 19:26:37 2022 +0100

    libxl: Introduce basic virtio-mmio support on Arm
    
    This patch introduces helpers to allocate Virtio MMIO params
    (IRQ and memory region) and create specific device node in
    the Guest device-tree with allocated params. In order to deal
    with multiple Virtio devices, reserve corresponding ranges.
    For now, we reserve 1MB for memory regions and 10 SPIs.
    
    As these helpers should be used for every Virtio device attached
    to the Guest, call them for Virtio disk(s).
    
    Please note, with statically allocated Virtio IRQs there is
    a risk of a clash with a physical IRQs of passthrough devices.
    For the first version, it's fine, but we should consider allocating
    the Virtio IRQs automatically. Thankfully, we know in advance which
    IRQs will be used for passthrough to be able to choose non-clashed
    ones.
    
    Signed-off-by: Julien Grall <julien.grall@xxxxxxx>
    Signed-off-by: Oleksandr Tyshchenko <oleksandr_tyshchenko@xxxxxxxx>
    Reviewed-by: Stefano Stabellini <sstabellini@xxxxxxxxxx>
    Reviewed-by: Anthony PERARD <anthony.perard@xxxxxxxxxx>
---
 tools/libs/light/libxl_arm.c  | 121 +++++++++++++++++++++++++++++++++++++++++-
 xen/include/public/arch-arm.h |   7 +++
 2 files changed, 126 insertions(+), 2 deletions(-)

diff --git a/tools/libs/light/libxl_arm.c b/tools/libs/light/libxl_arm.c
index 7dee2afd4b..866e58c66b 100644
--- a/tools/libs/light/libxl_arm.c
+++ b/tools/libs/light/libxl_arm.c
@@ -8,6 +8,46 @@
 #include <assert.h>
 #include <xen/device_tree_defs.h>
 
+/*
+ * There is no clear requirements for the total size of Virtio MMIO region.
+ * The size of control registers is 0x100 and device-specific configuration
+ * registers starts at the offset 0x100, however it's size depends on the 
device
+ * and the driver. Pick the biggest known size at the moment to cover most
+ * of the devices (also consider allowing the user to configure the size via
+ * config file for the one not conforming with the proposed value).
+ */
+#define VIRTIO_MMIO_DEV_SIZE   xen_mk_ullong(0x200)
+
+static uint64_t alloc_virtio_mmio_base(libxl__gc *gc, uint64_t 
*virtio_mmio_base)
+{
+    uint64_t base = *virtio_mmio_base;
+
+    /* Make sure we have enough reserved resources */
+    if (base + VIRTIO_MMIO_DEV_SIZE >
+        GUEST_VIRTIO_MMIO_BASE + GUEST_VIRTIO_MMIO_SIZE) {
+        LOG(ERROR, "Ran out of reserved range for Virtio MMIO BASE 
0x%"PRIx64"\n",
+            base);
+        return 0;
+    }
+    *virtio_mmio_base += VIRTIO_MMIO_DEV_SIZE;
+
+    return base;
+}
+
+static uint32_t alloc_virtio_mmio_irq(libxl__gc *gc, uint32_t *virtio_mmio_irq)
+{
+    uint32_t irq = *virtio_mmio_irq;
+
+    /* Make sure we have enough reserved resources */
+    if (irq > GUEST_VIRTIO_MMIO_SPI_LAST) {
+        LOG(ERROR, "Ran out of reserved range for Virtio MMIO IRQ %u\n", irq);
+        return 0;
+    }
+    (*virtio_mmio_irq)++;
+
+    return irq;
+}
+
 static const char *gicv_to_string(libxl_gic_version gic_version)
 {
     switch (gic_version) {
@@ -26,8 +66,10 @@ int libxl__arch_domain_prepare_config(libxl__gc *gc,
 {
     uint32_t nr_spis = 0;
     unsigned int i;
-    uint32_t vuart_irq;
-    bool vuart_enabled = false;
+    uint32_t vuart_irq, virtio_irq = 0;
+    bool vuart_enabled = false, virtio_enabled = false;
+    uint64_t virtio_mmio_base = GUEST_VIRTIO_MMIO_BASE;
+    uint32_t virtio_mmio_irq = GUEST_VIRTIO_MMIO_SPI_FIRST;
 
     /*
      * If pl011 vuart is enabled then increment the nr_spis to allow allocation
@@ -39,6 +81,35 @@ int libxl__arch_domain_prepare_config(libxl__gc *gc,
         vuart_enabled = true;
     }
 
+    for (i = 0; i < d_config->num_disks; i++) {
+        libxl_device_disk *disk = &d_config->disks[i];
+
+        if (disk->specification == LIBXL_DISK_SPECIFICATION_VIRTIO) {
+            disk->base = alloc_virtio_mmio_base(gc, &virtio_mmio_base);
+            if (!disk->base)
+                return ERROR_FAIL;
+
+            disk->irq = alloc_virtio_mmio_irq(gc, &virtio_mmio_irq);
+            if (!disk->irq)
+                return ERROR_FAIL;
+
+            if (virtio_irq < disk->irq)
+                virtio_irq = disk->irq;
+            virtio_enabled = true;
+
+            LOG(DEBUG, "Allocate Virtio MMIO params for Vdev %s: IRQ %u BASE 
0x%"PRIx64,
+                disk->vdev, disk->irq, disk->base);
+        }
+    }
+
+    /*
+     * Every virtio-mmio device uses one emulated SPI. If Virtio devices are
+     * present, make sure that we allocate enough SPIs for them.
+     * The resulting "nr_spis" needs to cover the highest possible SPI.
+     */
+    if (virtio_enabled)
+        nr_spis = max(nr_spis, virtio_irq - 32 + 1);
+
     for (i = 0; i < d_config->b_info.num_irqs; i++) {
         uint32_t irq = d_config->b_info.irqs[i];
         uint32_t spi;
@@ -58,6 +129,13 @@ int libxl__arch_domain_prepare_config(libxl__gc *gc,
             return ERROR_FAIL;
         }
 
+        /* The same check as for vpl011 */
+        if (virtio_enabled &&
+            (irq >= GUEST_VIRTIO_MMIO_SPI_FIRST && irq <= virtio_irq)) {
+            LOG(ERROR, "Physical IRQ %u conflicting with Virtio MMIO IRQ 
range\n", irq);
+            return ERROR_FAIL;
+        }
+
         if (irq < 32)
             continue;
 
@@ -787,6 +865,37 @@ static int make_vpci_node(libxl__gc *gc, void *fdt,
     return 0;
 }
 
+
+static int make_virtio_mmio_node(libxl__gc *gc, void *fdt,
+                                 uint64_t base, uint32_t irq)
+{
+    int res;
+    gic_interrupt intr;
+    const char *name = GCSPRINTF("virtio@%"PRIx64, base);
+
+    res = fdt_begin_node(fdt, name);
+    if (res) return res;
+
+    res = fdt_property_compat(gc, fdt, 1, "virtio,mmio");
+    if (res) return res;
+
+    res = fdt_property_regs(gc, fdt, GUEST_ROOT_ADDRESS_CELLS, 
GUEST_ROOT_SIZE_CELLS,
+                            1, base, VIRTIO_MMIO_DEV_SIZE);
+    if (res) return res;
+
+    set_interrupt(intr, irq, 0xf, DT_IRQ_TYPE_EDGE_RISING);
+    res = fdt_property_interrupts(gc, fdt, &intr, 1);
+    if (res) return res;
+
+    res = fdt_property(fdt, "dma-coherent", NULL, 0);
+    if (res) return res;
+
+    res = fdt_end_node(fdt);
+    if (res) return res;
+
+    return 0;
+}
+
 static const struct arch_info *get_arch_info(libxl__gc *gc,
                                              const struct xc_dom_image *dom)
 {
@@ -988,6 +1097,7 @@ static int libxl__prepare_dtb(libxl__gc *gc, 
libxl_domain_config *d_config,
     size_t fdt_size = 0;
     int pfdt_size = 0;
     libxl_domain_build_info *const info = &d_config->b_info;
+    unsigned int i;
 
     const libxl_version_info *vers;
     const struct arch_info *ainfo;
@@ -1094,6 +1204,13 @@ next_resize:
         if (d_config->num_pcidevs)
             FDT( make_vpci_node(gc, fdt, ainfo, dom) );
 
+        for (i = 0; i < d_config->num_disks; i++) {
+            libxl_device_disk *disk = &d_config->disks[i];
+
+            if (disk->specification == LIBXL_DISK_SPECIFICATION_VIRTIO)
+                FDT( make_virtio_mmio_node(gc, fdt, disk->base, disk->irq) );
+        }
+
         if (pfdt)
             FDT( copy_partial_fdt(gc, fdt, pfdt) );
 
diff --git a/xen/include/public/arch-arm.h b/xen/include/public/arch-arm.h
index ab05fe12b0..c8b6058d3a 100644
--- a/xen/include/public/arch-arm.h
+++ b/xen/include/public/arch-arm.h
@@ -407,6 +407,10 @@ typedef uint64_t xen_callback_t;
 
 /* Physical Address Space */
 
+/* Virtio MMIO mappings */
+#define GUEST_VIRTIO_MMIO_BASE   xen_mk_ullong(0x02000000)
+#define GUEST_VIRTIO_MMIO_SIZE   xen_mk_ullong(0x00100000)
+
 /*
  * vGIC mappings: Only one set of mapping is used by the guest.
  * Therefore they can overlap.
@@ -493,6 +497,9 @@ typedef uint64_t xen_callback_t;
 
 #define GUEST_VPL011_SPI        32
 
+#define GUEST_VIRTIO_MMIO_SPI_FIRST   33
+#define GUEST_VIRTIO_MMIO_SPI_LAST    43
+
 /* PSCI functions */
 #define PSCI_cpu_suspend 0
 #define PSCI_cpu_off     1
--
generated by git-patchbot for /home/xen/git/xen.git#staging



 


Rackspace

Lists.xenproject.org is hosted with RackSpace, monitoring our
servers 24x7x365 and backed by RackSpace's Fanatical Support®.