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[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] Re: [PATCH v12 03/12] xen/arm: permit non direct-mapped Dom0 construction
Hi Michal,
On Mon, Dec 16, 2024 at 1:08 PM Michal Orzel <michal.orzel@xxxxxxx> wrote:
>
> On 13/12/2024 17:28, Carlo Nonato wrote:
> >
> > Cache coloring requires Dom0 not to be direct-mapped because of its non
> > contiguous mapping nature, so allocate_memory() is needed in this case.
> > 8d2c3ab18cc1 ("arm/dom0less: put dom0less feature code in a separate
> > module")
> > moved allocate_memory() in dom0less_build.c. In order to use it
> > in Dom0 construction bring it back to domain_build.c and declare it in
> > domain_build.h.
> >
> > Adapt the implementation of allocate_memory() so that it uses the host
> > layout when called on the hwdom, via find_unallocated_memory(). Take the
> > opportunity to keep the parameter order consistent with
> > rangeset_report_ranges() and move the membanks struct after the callback
> > function in find_unallocated_memory().
> Why? What benefit does this change (that is irrelevant to the goal of this
> patch) provide?
You're right, it's irrelevant to this patch. Do you think it can be done in a
separate patch? If nothing else, find_unallocated_memory() appears to be
called 2 times while rangeset_report_ranges() 11 times.
> > Introduce add_hwdom_free_regions() callback to add hwdom banks in descending
> > order.
> >
> > Signed-off-by: Carlo Nonato <carlo.nonato@xxxxxxxxxxxxxxx>
> > ---
> > v12:
> > - used the new generic find_unallocated_memory()
> > - added add_hwdom_free_regions() callback
> > v11:
> > - GUEST_RAM_BANKS instead of hardcoding the number of banks in
> > allocate_memory()
> > - hwdom_ext_regions -> hwdom_free_mem in allocate_memory()
> > - added a comment in allocate_memory() when skipping small banks
> > v10:
> > - fixed a compilation bug that happened when dom0less support was disabled
> > v9:
> > - no changes
> > v8:
> > - patch adapted to new changes to allocate_memory()
> > v7:
> > - allocate_memory() now uses the host layout when called on the hwdom
> > v6:
> > - new patch
> > ---
> > xen/arch/arm/dom0less-build.c | 44 -------
> > xen/arch/arm/domain_build.c | 164 +++++++++++++++++++++++-
> > xen/arch/arm/include/asm/domain_build.h | 4 +
> > 3 files changed, 161 insertions(+), 51 deletions(-)
> >
> > diff --git a/xen/arch/arm/dom0less-build.c b/xen/arch/arm/dom0less-build.c
> > index d93a85434e..67b1503647 100644
> > --- a/xen/arch/arm/dom0less-build.c
> > +++ b/xen/arch/arm/dom0less-build.c
> > @@ -49,50 +49,6 @@ bool __init is_dom0less_mode(void)
> > return ( !dom0found && domUfound );
> > }
> >
> > -static void __init allocate_memory(struct domain *d, struct kernel_info
> > *kinfo)
> > -{
> > - struct membanks *mem = kernel_info_get_mem(kinfo);
> > - unsigned int i;
> > - paddr_t bank_size;
> > -
> > - printk(XENLOG_INFO "Allocating mappings totalling %ldMB for %pd:\n",
> > - /* Don't want format this as PRIpaddr (16 digit hex) */
> > - (unsigned long)(kinfo->unassigned_mem >> 20), d);
> > -
> > - mem->nr_banks = 0;
> > - bank_size = MIN(GUEST_RAM0_SIZE, kinfo->unassigned_mem);
> > - if ( !allocate_bank_memory(kinfo, gaddr_to_gfn(GUEST_RAM0_BASE),
> > - bank_size) )
> > - goto fail;
> > -
> > - bank_size = MIN(GUEST_RAM1_SIZE, kinfo->unassigned_mem);
> > - if ( !allocate_bank_memory(kinfo, gaddr_to_gfn(GUEST_RAM1_BASE),
> > - bank_size) )
> > - goto fail;
> > -
> > - if ( kinfo->unassigned_mem )
> > - goto fail;
> > -
> > - for( i = 0; i < mem->nr_banks; i++ )
> > - {
> > - printk(XENLOG_INFO "%pd BANK[%d] %#"PRIpaddr"-%#"PRIpaddr"
> > (%ldMB)\n",
> > - d,
> > - i,
> > - mem->bank[i].start,
> > - mem->bank[i].start + mem->bank[i].size,
> > - /* Don't want format this as PRIpaddr (16 digit hex) */
> > - (unsigned long)(mem->bank[i].size >> 20));
> > - }
> > -
> > - return;
> > -
> > -fail:
> > - panic("Failed to allocate requested domain memory."
> > - /* Don't want format this as PRIpaddr (16 digit hex) */
> > - " %ldKB unallocated. Fix the VMs configurations.\n",
> > - (unsigned long)kinfo->unassigned_mem >> 10);
> > -}
> > -
> > #ifdef CONFIG_VGICV2
> > static int __init make_gicv2_domU_node(struct kernel_info *kinfo)
> > {
> > diff --git a/xen/arch/arm/domain_build.c b/xen/arch/arm/domain_build.c
> > index adf26f2778..bfcff99194 100644
> > --- a/xen/arch/arm/domain_build.c
> > +++ b/xen/arch/arm/domain_build.c
> > @@ -2,6 +2,7 @@
> > #include <xen/init.h>
> > #include <xen/compile.h>
> > #include <xen/lib.h>
> > +#include <xen/llc-coloring.h>
> > #include <xen/mm.h>
> > #include <xen/param.h>
> > #include <xen/domain_page.h>
> > @@ -416,7 +417,6 @@ static void __init allocate_memory_11(struct domain *d,
> > }
> > }
> >
> > -#ifdef CONFIG_DOM0LESS_BOOT
> > bool __init allocate_domheap_memory(struct domain *d, paddr_t tot_size,
> > alloc_domheap_mem_cb cb, void *extra)
> > {
> > @@ -508,7 +508,6 @@ bool __init allocate_bank_memory(struct kernel_info
> > *kinfo, gfn_t sgfn,
> >
> > return true;
> > }
> > -#endif
> >
> > /*
> > * When PCI passthrough is available we want to keep the
> > @@ -900,6 +899,52 @@ int __init add_ext_regions(unsigned long s_gfn,
> > unsigned long e_gfn,
> > return 0;
> > }
> >
> > +static int __init add_hwdom_free_regions(unsigned long s_gfn,
> > + unsigned long e_gfn, void *data)
> > +{
> > + struct membanks *free_regions = data;
> > + paddr_t start, size;
> > + paddr_t s = pfn_to_paddr(s_gfn);
> > + paddr_t e = pfn_to_paddr(e_gfn);
> > + unsigned int i, j;
> > +
> > + if ( free_regions->nr_banks >= free_regions->max_banks )
> > + return 0;
> > +
> > + /*
> > + * Both start and size of the free region should be 2MB aligned to
> > + * potentially allow superpage mapping.
> > + */
> > + start = (s + SZ_2M - 1) & ~(SZ_2M - 1);
> > + if ( start > e )
> > + return 0;
> > +
> > + /*
> > + * e is actually "end-1" because it is called by rangeset functions
> > + * which are inclusive of the last address.
> > + */
> > + e += 1;
> > + size = (e - start) & ~(SZ_2M - 1);
> > +
> > + /* Find the insert position (descending order). */
> > + for ( i = 0; i < free_regions->nr_banks ; i++)
> CODING_STYLE:
> for ( i = 0; i < free_regions->nr_banks; i++ )
>
> > + if ( size > free_regions->bank[i].size )
> > + break;
> > +
> > + /* Move the other banks to make space. */
> > + for ( j = free_regions->nr_banks; j > i ; j-- )
> > + {
> > + free_regions->bank[j].start = free_regions->bank[j - 1].start;
> > + free_regions->bank[j].size = free_regions->bank[j - 1].size;
> > + }
> > +
> > + free_regions->bank[i].start = start;
> > + free_regions->bank[i].size = size;
> > + free_regions->nr_banks++;
> The algorithm looks good. In my head I thought you will use sort() after
> adding all the banks, but
> I'm not sure which solution is more efficient. Probably yours and it avoids
> implementing cmp and swap functions.
>
> > +
> > + return 0;
> > +}
> > +
> > /*
> > * Find unused regions of Host address space which can be exposed to domain
> > * using the host memory layout. In order to calculate regions we exclude
> > every
> > @@ -908,10 +953,10 @@ int __init add_ext_regions(unsigned long s_gfn,
> > unsigned long e_gfn,
> > static int __init find_unallocated_memory(const struct kernel_info *kinfo,
> > const struct membanks
> > *mem_banks[],
> > unsigned int nr_mem_banks,
> > - struct membanks *free_regions,
> > int (*cb)(unsigned long s_gfn,
> > unsigned long e_gfn,
> > - void *data))
> > + void *data),
> > + struct membanks *free_regions)
> > {
> > const struct membanks *mem = bootinfo_get_mem();
> > struct rangeset *unalloc_mem;
> > @@ -977,6 +1022,108 @@ out:
> > return res;
> > }
> >
> > +void __init allocate_memory(struct domain *d, struct kernel_info *kinfo)
> > +{
> > + struct membanks *mem = kernel_info_get_mem(kinfo);
> > + unsigned int i, nr_banks = GUEST_RAM_BANKS;
> > + struct membanks *hwdom_free_mem = NULL;
> > +
> > + printk(XENLOG_INFO "Allocating mappings totalling %ldMB for %pd:\n",
> > + /* Don't want format this as PRIpaddr (16 digit hex) */
> > + (unsigned long)(kinfo->unassigned_mem >> 20), d);
> > +
> > + mem->nr_banks = 0;
> > + /*
> > + * Use host memory layout for hwdom. Only case for this is when LLC
> > coloring
> > + * is enabled.
> > + */
> > + if ( is_hardware_domain(d) )
> > + {
> > + struct membanks *gnttab = xzalloc_flex_struct(struct membanks,
> > bank, 1);
> > + /*
> > + * Exclude the following regions:
> > + * 1) Remove reserved memory
> > + * 2) Grant table assigned to Dom0
> Can we not mention 'Dom0'? In the future hwdom may not necessarily be dom0.
> Especially that
> in other places you mention hwdom.
>
> > + */
> > + const struct membanks *mem_banks[] = {
> > + bootinfo_get_reserved_mem(),
> > + gnttab,
> > + };
> > +
> > + ASSERT(llc_coloring_enabled);
> Remove this assert. There's nothing LLC special here and this could be
> re-used in the future
> to provide non 1:1 hwdom.
>
> > +
> > + if ( !gnttab )
> > + goto fail;
> > +
> > + gnttab->nr_banks = 1;
> > + gnttab->bank[0].start = kinfo->gnttab_start;
> > + gnttab->bank[0].size = kinfo->gnttab_start + kinfo->gnttab_size;
> Incorrect. You assign to 'end' to'size'. It should simply be:
> gnttab->bank[0].size = kinfo->gnttab_size.
>
> > +
> > + hwdom_free_mem = xzalloc_flex_struct(struct membanks, bank,
> > + NR_MEM_BANKS);
> > + if ( !hwdom_free_mem )
> > + goto fail;
> > +
> > + hwdom_free_mem->max_banks = NR_MEM_BANKS;
> > +
> > + if ( find_unallocated_memory(kinfo, mem_banks,
> > ARRAY_SIZE(mem_banks),
> > + add_hwdom_free_regions,
> > hwdom_free_mem) )
> > + goto fail;
> > +
> > + nr_banks = hwdom_free_mem->nr_banks;
> > + xfree(gnttab);
> > + }
> > +
> > + for ( i = 0; kinfo->unassigned_mem > 0 && nr_banks > 0; i++,
> > nr_banks-- )
> > + {
> > + paddr_t bank_start, bank_size;
> > +
> > + if ( is_hardware_domain(d) )
> > + {
> > + bank_start = hwdom_free_mem->bank[i].start;
> > + bank_size = hwdom_free_mem->bank[i].size;
> > + }
> > + else
> > + {
> > + const uint64_t bankbase[] = GUEST_RAM_BANK_BASES;
> > + const uint64_t banksize[] = GUEST_RAM_BANK_SIZES;
> > +
> > + if ( i >= GUEST_RAM_BANKS )
> > + goto fail;
> > +
> > + bank_start = bankbase[i];
> > + bank_size = banksize[i];
> > + }
> > +
> > + bank_size = MIN(bank_size, kinfo->unassigned_mem);
> > + if ( !allocate_bank_memory(kinfo, gaddr_to_gfn(bank_start),
> > bank_size) )
> > + goto fail;
> > + }
> > +
> > + if ( kinfo->unassigned_mem )
> > + goto fail;
> > +
> > + for( i = 0; i < mem->nr_banks; i++ )
> > + {
> > + printk(XENLOG_INFO "%pd BANK[%d] %#"PRIpaddr"-%#"PRIpaddr"
> > (%ldMB)\n",
> > + d,
> > + i,
> > + mem->bank[i].start,
> > + mem->bank[i].start + mem->bank[i].size,
> > + /* Don't want format this as PRIpaddr (16 digit hex) */
> > + (unsigned long)(mem->bank[i].size >> 20));
> > + }
> > +
> > + xfree(hwdom_free_mem);
> > + return;
> > +
> > +fail:
> > + panic("Failed to allocate requested domain memory."
> > + /* Don't want format this as PRIpaddr (16 digit hex) */
> > + " %ldKB unallocated. Fix the VMs configurations.\n",
> > + (unsigned long)kinfo->unassigned_mem >> 10);
> > +}
> > +
> > static int __init handle_pci_range(const struct dt_device_node *dev,
> > uint64_t addr, uint64_t len, void *data)
> > {
> > @@ -1176,7 +1323,7 @@ static int __init find_host_extended_regions(const
> > struct kernel_info *kinfo,
> > gnttab->bank[0].size = kinfo->gnttab_size;
> >
> > res = find_unallocated_memory(kinfo, mem_banks, ARRAY_SIZE(mem_banks),
> > - ext_regions, add_ext_regions);
> > + add_ext_regions, ext_regions);
> > xfree(gnttab);
> >
> > return res;
> > @@ -1235,7 +1382,7 @@ int __init make_hypervisor_node(struct domain *d,
> >
> > ext_regions->max_banks = NR_MEM_BANKS;
> >
> > - if ( is_domain_direct_mapped(d) )
> > + if ( domain_use_host_layout(d) )
> > {
> > if ( !is_iommu_enabled(d) )
> > res = find_host_extended_regions(kinfo, ext_regions);
> > @@ -2164,8 +2311,11 @@ static int __init construct_dom0(struct domain *d)
> > /* type must be set before allocate_memory */
> > d->arch.type = kinfo.type;
> > #endif
> > - allocate_memory_11(d, &kinfo);
> > find_gnttab_region(d, &kinfo);
> This re-ordering should be mentioned in commit msg.
>
> > + if ( is_domain_direct_mapped(d) )
> > + allocate_memory_11(d, &kinfo);
> > + else
> > + allocate_memory(d, &kinfo);
> >
> > rc = process_shm_chosen(d, &kinfo);
> > if ( rc < 0 )
> > diff --git a/xen/arch/arm/include/asm/domain_build.h
> > b/xen/arch/arm/include/asm/domain_build.h
> > index e712afbc7f..b0d646e173 100644
> > --- a/xen/arch/arm/include/asm/domain_build.h
> > +++ b/xen/arch/arm/include/asm/domain_build.h
> > @@ -11,6 +11,7 @@ bool allocate_domheap_memory(struct domain *d, paddr_t
> > tot_size,
> > alloc_domheap_mem_cb cb, void *extra);
> > bool allocate_bank_memory(struct kernel_info *kinfo, gfn_t sgfn,
> > paddr_t tot_size);
> > +void allocate_memory(struct domain *d, struct kernel_info *kinfo);
> > int construct_domain(struct domain *d, struct kernel_info *kinfo);
> > int domain_fdt_begin_node(void *fdt, const char *name, uint64_t unit);
> > int make_chosen_node(const struct kernel_info *kinfo);
> > @@ -54,6 +55,9 @@ static inline int prepare_acpi(struct domain *d, struct
> > kernel_info *kinfo)
> > int prepare_acpi(struct domain *d, struct kernel_info *kinfo);
> > #endif
> >
> > +typedef int (*add_free_regions_fn)(unsigned long s_gfn, unsigned long
> > e_gfn,
> > + void *data);
> Random code? Remove.
>
> With the remarks addressed:
> Reviewed-by: Michal Orzel <michal.orzel@xxxxxxx>
>
> ~Michal
Thanks.
- Carlo
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