Xen project Mailing List

On Fri, Apr 22, 2022 at 5:43 AM Jiamei Xie <Jiamei.Xie@xxxxxxx> wrote:

Hi Oleksandr,

Hi Jiamei

[Sorry for the possible format issues]

I am happy to keep my T-b tag. I have tested this latest patch series and it works.

Thank you for the testing and confirmation!

Regards,
Jiamei Xie

> -----Original Message-----
> From: Xen-devel <xen-devel-bounces@xxxxxxxxxxxxxxxxxxxx> On Behalf Of
> Oleksandr Tyshchenko
> Sent: 2022年4月9日 2:21
> To: xen-devel@xxxxxxxxxxxxxxxxxxxx
> Cc: Julien Grall <Julien.Grall@xxxxxxx>; Wei Liu <wl@xxxxxxx>; Anthony
> PERARD <anthony.perard@xxxxxxxxxx>; Juergen Gross <jgross@xxxxxxxx>;
> Stefano Stabellini <sstabellini@xxxxxxxxxx>; Julien Grall <julien@xxxxxxx>;
> Bertrand Marquis <Bertrand.Marquis@xxxxxxx>; Volodymyr Babchuk
> <Volodymyr_Babchuk@xxxxxxxx>; Jiamei Xie <Jiamei.Xie@xxxxxxx>;
> Henry Wang <Henry.Wang@xxxxxxx>; Oleksandr Tyshchenko
> <oleksandr_tyshchenko@xxxxxxxx>
> Subject: [PATCH V7 2/2] libxl: Introduce basic virtio-mmio support on Arm
>
> From: Julien Grall <julien.grall@xxxxxxx>
>
> 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>
> Tested-by: Jiamei Xie <Jiamei.xie@xxxxxxx>
> Reviewed-by: Henry Wang <Henry.Wang@xxxxxxx>
> ---
> @Jiamei, @Henry I decided to leave your T-b and R-b tags with the minor
> change I made, are you still happy with that?
>
> s/if (disk->virtio)/if (disk->protocol == LIBXL_DISK_PROTOCOL_VIRTIO_MMIO)
>
> Please note, this is a split/cleanup/hardening of Julien's PoC:
> "Add support for Guest IO forwarding to a device emulator"
>
> Changes RFC -> V1:
> - was squashed with:
> "[RFC PATCH V1 09/12] libxl: Handle virtio-mmio irq in more correct way"
> "[RFC PATCH V1 11/12] libxl: Insert "dma-coherent" property into virtio-
> mmio device node"
> "[RFC PATCH V1 12/12] libxl: Fix duplicate memory node in DT"
> - move VirtIO MMIO #define-s to xen/include/public/arch-arm.h
>
> Changes V1 -> V2:
> - update the author of a patch
>
> Changes V2 -> V3:
> - no changes
>
> Changes V3 -> V4:
> - no changes
>
> Changes V4 -> V5:
> - split the changes, change the order of the patches
> - drop an extra "virtio" configuration option
> - update patch description
> - use CONTAINER_OF instead of own implementation
> - reserve ranges for Virtio MMIO params and put them
> in correct location
> - create helpers to allocate Virtio MMIO params, add
> corresponding sanity-сhecks
> - add comment why MMIO size 0x200 is chosen
> - update debug print
> - drop Wei's T-b
>
> Changes V5 -> V6:
> - rebase on current staging
>
> Changes V6 -> V7:
> - rebase on current staging
> - add T-b and R-b tags
> - update according to the recent changes to
> "libxl: Add support for Virtio disk configuration"
> ---
> tools/libs/light/libxl_arm.c | 131
> +++++++++++++++++++++++++++++++++++++++++-
> xen/include/public/arch-arm.h | 7 +++
> 2 files changed, 136 insertions(+), 2 deletions(-)
>
> diff --git a/tools/libs/light/libxl_arm.c b/tools/libs/light/libxl_arm.c
> index eef1de0..8132a47 100644
> --- a/tools/libs/light/libxl_arm.c
> +++ b/tools/libs/light/libxl_arm.c
> @@ -8,6 +8,56 @@
> #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 virtio_mmio_base;
> +static uint32_t virtio_mmio_irq;
> +
> +static void init_virtio_mmio_params(void)
> +{
> + virtio_mmio_base = GUEST_VIRTIO_MMIO_BASE;
> + virtio_mmio_irq = GUEST_VIRTIO_MMIO_SPI_FIRST;
> +}
> +
> +static uint64_t alloc_virtio_mmio_base(libxl__gc *gc)
> +{
> + uint64_t base = virtio_mmio_base;
> +
> + /* Make sure we have enough reserved resources */
> + if ((virtio_mmio_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",
> + virtio_mmio_base);
> + return 0;
> + }
> + virtio_mmio_base += VIRTIO_MMIO_DEV_SIZE;
> +
> + return base;
> +}
> +
> +static uint32_t alloc_virtio_mmio_irq(libxl__gc *gc)
> +{
> + uint32_t irq = virtio_mmio_irq;
> +
> + /* Make sure we have enough reserved resources */
> + if (virtio_mmio_irq > GUEST_VIRTIO_MMIO_SPI_LAST) {
> + LOG(ERROR, "Ran out of reserved range for Virtio MMIO IRQ %u\n",
> + virtio_mmio_irq);
> + return 0;
> + }
> + virtio_mmio_irq++;
> +
> + return irq;
> +}
> +
> static const char *gicv_to_string(libxl_gic_version gic_version)
> {
> switch (gic_version) {
> @@ -26,8 +76,8 @@ 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;
>
> /*
> * If pl011 vuart is enabled then increment the nr_spis to allow allocation
> @@ -39,6 +89,35 @@ int libxl__arch_domain_prepare_config(libxl__gc *gc,
> vuart_enabled = true;
> }
>
> + /*
> + * Virtio MMIO params are non-unique across the whole system and
> must be
> + * initialized for every new guest.
> + */
> + init_virtio_mmio_params();
> + for (i = 0; i < d_config->num_disks; i++) {
> + libxl_device_disk *disk = &d_config->disks[i];
> +
> + if (disk->protocol == LIBXL_DISK_PROTOCOL_VIRTIO_MMIO) {
> + disk->base = alloc_virtio_mmio_base(gc);
> + if (!disk->base)
> + return ERROR_FAIL;
> +
> + disk->irq = alloc_virtio_mmio_irq(gc);
> + 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);
> + }
> + }
> +
> + if (virtio_enabled)
> + 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 +137,13 @@ 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 +873,39 @@ 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;
> + /* Placeholder for virtio@ + a 64-bit number + \0 */
> + char buf[24];
> +
> + snprintf(buf, sizeof(buf), "virtio@%"PRIx64, base);
> + res = fdt_begin_node(fdt, buf);
> + 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 +1107,7 @@ 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 +1214,13 @@ 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->protocol == LIBXL_DISK_PROTOCOL_VIRTIO_MMIO)
> + 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 ab05fe1..c8b6058 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
> --
> 2.7.4
>

Regards,

Oleksandr Tyshchenko

Re: [PATCH V7 2/2] libxl: Introduce basic virtio-mmio support on Arm