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[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] Re: [PATCH V5 3/3] xen/arm: Updates for extended regions support
On Wed, 6 Oct 2021, Oleksandr Tyshchenko wrote:
> From: Oleksandr Tyshchenko <oleksandr_tyshchenko@xxxxxxxx>
>
> This is a follow-up of
> "b6fe410 xen/arm: Add handling of extended regions for Dom0"
>
> Add various in-code comments, update Xen hypervisor device tree
> bindings text, change the log level for some prints and clarify
> format specifier, reuse dt_for_each_range() to avoid open-coding
> in find_memory_holes().
>
> Signed-off-by: Oleksandr Tyshchenko <oleksandr_tyshchenko@xxxxxxxx>
Thanks for the patch, it looks like you addressed all Julien's comments
well. A couple of minor issues below.
> ---
> New patch
> ---
> docs/misc/arm/device-tree/guest.txt | 12 ++--
> xen/arch/arm/domain_build.c | 108
> ++++++++++++++++++++++--------------
> 2 files changed, 73 insertions(+), 47 deletions(-)
>
> diff --git a/docs/misc/arm/device-tree/guest.txt
> b/docs/misc/arm/device-tree/guest.txt
> index 418f1e9..c115751 100644
> --- a/docs/misc/arm/device-tree/guest.txt
> +++ b/docs/misc/arm/device-tree/guest.txt
> @@ -7,10 +7,14 @@ the following properties:
> compatible = "xen,xen-<version>", "xen,xen";
> where <version> is the version of the Xen ABI of the platform.
>
> -- reg: specifies the base physical address and size of a region in
> - memory where the grant table should be mapped to, using an
> - HYPERVISOR_memory_op hypercall. The memory region is large enough to map
> - the whole grant table (it is larger or equal to gnttab_max_grant_frames()).
> +- reg: specifies the base physical address and size of the regions in memory
> + where the special resources should be mapped to, using an
> HYPERVISOR_memory_op
> + hypercall.
> + Region 0 is reserved for mapping grant table, it must be always present.
> + The memory region is large enough to map the whole grant table (it is
> larger
> + or equal to gnttab_max_grant_frames()).
> + Regions 1...N are extended regions (unused address space) for mapping
> foreign
> + GFNs and grants, they might be absent if there is nothing to expose.
> This property is unnecessary when booting Dom0 using ACPI.
>
> - interrupts: the interrupt used by Xen to inject event notifications.
> diff --git a/xen/arch/arm/domain_build.c b/xen/arch/arm/domain_build.c
> index c5afbe2..d9f40d4 100644
> --- a/xen/arch/arm/domain_build.c
> +++ b/xen/arch/arm/domain_build.c
> @@ -898,7 +898,10 @@ static int __init add_ext_regions(unsigned long s,
> unsigned long e, void *data)
> if ( ext_regions->nr_banks >= ARRAY_SIZE(ext_regions->bank) )
> return 0;
>
> - /* Both start and size of the extended region should be 2MB aligned */
> + /*
> + * Both start and size of the extended region should be 2MB aligned to
> + * potentially allow superpage mapping.
> + */
> start = (s + SZ_2M - 1) & ~(SZ_2M - 1);
> if ( start > e )
> return 0;
> @@ -909,6 +912,12 @@ static int __init add_ext_regions(unsigned long s,
> unsigned long e, void *data)
> */
> e += 1;
> size = (e - start) & ~(SZ_2M - 1);
> +
> + /*
> + * Reasonable size. Not too little to pick up small ranges which are
> + * not quite useful itself but increase bookkeeping and not too much
^ remove itself ^ large
> + * to skip a large proportion of unused address space.
> + */
> if ( size < MB(64) )
> return 0;
>
> @@ -919,6 +928,14 @@ static int __init add_ext_regions(unsigned long s,
> unsigned long e, void *data)
> return 0;
> }
>
> +/*
> + * Find unused regions of Host address space which can be exposed to Dom0
> + * as extended regions for the special memory mappings. In order to calculate
> + * regions we exclude every assigned to Dom0 region from the Host RAM:
^ region assigned ^ remove
> + * - domain RAM
> + * - reserved-memory
> + * - grant table space
> + */
> static int __init find_unallocated_memory(const struct kernel_info *kinfo,
> struct meminfo *ext_regions)
> {
> @@ -942,7 +959,7 @@ static int __init find_unallocated_memory(const struct
> kernel_info *kinfo,
> res = rangeset_add_range(unalloc_mem, start, end - 1);
> if ( res )
> {
> - printk(XENLOG_ERR "Failed to add: %#"PRIx64"->%#"PRIx64"\n",
> + printk(XENLOG_ERR "Failed to add: %#"PRIpaddr"->%#"PRIpaddr"\n",
> start, end);
> goto out;
> }
> @@ -956,7 +973,7 @@ static int __init find_unallocated_memory(const struct
> kernel_info *kinfo,
> res = rangeset_remove_range(unalloc_mem, start, end - 1);
> if ( res )
> {
> - printk(XENLOG_ERR "Failed to remove: %#"PRIx64"->%#"PRIx64"\n",
> + printk(XENLOG_ERR "Failed to remove:
> %#"PRIpaddr"->%#"PRIpaddr"\n",
> start, end);
> goto out;
> }
> @@ -971,7 +988,7 @@ static int __init find_unallocated_memory(const struct
> kernel_info *kinfo,
> res = rangeset_remove_range(unalloc_mem, start, end - 1);
> if ( res )
> {
> - printk(XENLOG_ERR "Failed to remove: %#"PRIx64"->%#"PRIx64"\n",
> + printk(XENLOG_ERR "Failed to remove:
> %#"PRIpaddr"->%#"PRIpaddr"\n",
> start, end);
> goto out;
> }
> @@ -983,7 +1000,7 @@ static int __init find_unallocated_memory(const struct
> kernel_info *kinfo,
> res = rangeset_remove_range(unalloc_mem, start, end - 1);
> if ( res )
> {
> - printk(XENLOG_ERR "Failed to remove: %#"PRIx64"->%#"PRIx64"\n",
> + printk(XENLOG_ERR "Failed to remove: %#"PRIpaddr"->%#"PRIpaddr"\n",
> start, end);
> goto out;
> }
> @@ -1003,6 +1020,35 @@ out:
> return res;
> }
>
> +static int __init handle_pci_range(const struct dt_device_node *dev,
> + u64 addr, u64 len, void *data)
> +{
> + struct rangeset *mem_holes = data;
> + paddr_t start, end;
> + int res;
> +
> + start = addr & PAGE_MASK;
> + end = PAGE_ALIGN(addr + len);
> + res = rangeset_remove_range(mem_holes, start, end - 1);
> + if ( res )
> + {
> + printk(XENLOG_ERR "Failed to remove: %#"PRIpaddr"->%#"PRIpaddr"\n",
> + start, end);
> + return res;
> + }
> +
> + return 0;
> +}
> +
> +/*
> + * Find the holes in the Host DT which can be exposed to Dom0 as extended
> + * regions for the special memory mappings. In order to calculate regions
> + * we exclude every addressable memory region described by "reg" and "ranges"
> + * properties from the maximum possible addressable physical memory range:
> + * - MMIO
> + * - Host RAM
> + * - PCI bar
^ PCI aperture
> + */
> static int __init find_memory_holes(const struct kernel_info *kinfo,
> struct meminfo *ext_regions)
> {
> @@ -1024,7 +1070,7 @@ static int __init find_memory_holes(const struct
> kernel_info *kinfo,
> res = rangeset_add_range(mem_holes, start, end);
> if ( res )
> {
> - printk(XENLOG_ERR "Failed to add: %#"PRIx64"->%#"PRIx64"\n",
> + printk(XENLOG_ERR "Failed to add: %#"PRIpaddr"->%#"PRIpaddr"\n",
> start, end);
> goto out;
> }
> @@ -1055,49 +1101,25 @@ static int __init find_memory_holes(const struct
> kernel_info *kinfo,
> res = rangeset_remove_range(mem_holes, start, end - 1);
> if ( res )
> {
> - printk(XENLOG_ERR "Failed to remove:
> %#"PRIx64"->%#"PRIx64"\n",
> + printk(XENLOG_ERR "Failed to remove:
> %#"PRIpaddr"->%#"PRIpaddr"\n",
> start, end);
> goto out;
> }
> }
>
> - if ( dt_device_type_is_equal(np, "pci" ) )
> + if ( dt_device_type_is_equal(np, "pci") )
> {
> - unsigned int range_size, nr_ranges;
> - int na, ns, pna;
> - const __be32 *ranges;
> - u32 len;
> -
> /*
> - * Looking for non-empty ranges property which in this context
> - * describes the PCI host bridge aperture.
> + * The ranges property in this context describes the PCI host
> + * bridge aperture. It shall be absent if no addresses are mapped
> + * through the bridge.
> */
> - ranges = dt_get_property(np, "ranges", &len);
> - if ( !ranges || !len )
> + if ( !dt_get_property(np, "ranges", NULL) )
> continue;
>
> - pna = dt_n_addr_cells(np);
> - na = dt_child_n_addr_cells(np);
> - ns = dt_child_n_size_cells(np);
> - range_size = pna + na + ns;
> - nr_ranges = len / sizeof(__be32) / range_size;
> -
> - for ( i = 0; i < nr_ranges; i++, ranges += range_size )
> - {
> - /* Skip the child address and get the parent (CPU) address */
> - addr = dt_read_number(ranges + na, pna);
> - size = dt_read_number(ranges + na + pna, ns);
> -
> - start = addr & PAGE_MASK;
> - end = PAGE_ALIGN(addr + size);
> - res = rangeset_remove_range(mem_holes, start, end - 1);
> - if ( res )
> - {
> - printk(XENLOG_ERR "Failed to remove:
> %#"PRIx64"->%#"PRIx64"\n",
> - start, end);
> - goto out;
> - }
> - }
> + res = dt_for_each_range(np, &handle_pci_range, mem_holes);
> + if ( res )
> + goto out;
> }
> }
>
> @@ -1152,12 +1174,12 @@ static int __init make_hypervisor_node(struct domain
> *d,
>
> if ( !opt_ext_regions )
> {
> - printk(XENLOG_DEBUG "The extended regions support is disabled\n");
> + printk(XENLOG_INFO "The extended regions support is disabled\n");
> nr_ext_regions = 0;
> }
> else if ( is_32bit_domain(d) )
> {
> - printk(XENLOG_DEBUG "The extended regions are only supported for
> 64-bit guest currently\n");
> + printk(XENLOG_WARNING "The extended regions are only supported for
> 64-bit guest currently\n");
> nr_ext_regions = 0;
> }
> else
> @@ -1193,8 +1215,8 @@ static int __init make_hypervisor_node(struct domain *d,
> u64 start = ext_regions->bank[i].start;
> u64 size = ext_regions->bank[i].size;
>
> - dt_dprintk("Extended region %d: %#"PRIx64"->%#"PRIx64"\n",
> - i, start, start + size);
> + printk("Extended region %d: %#"PRIx64"->%#"PRIx64"\n",
> + i, start, start + size);
Also should be PRIpaddr
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