For 1:1 direct-mapped dom0less DomUs, the magic pages should not clash
with any RAM region. To find a proper region for guest magic pages,
we can reuse the logic of finding domain extended regions.
Extract the logic of finding domain extended regions to a helper
function named find_unused_memory() and use it to find unallocated
spaces for magic pages before make_hypervisor_node(). The result magic
page region is added to the reserved memory section of the bootinfo so
that it is carved out from the extended regions.
Reported-by: Alec Kwapis <alec.kwa...@medtronic.com>
Signed-off-by: Henry Wang <xin.wa...@amd.com>
---
v2:
- New patch
---
xen/arch/arm/dom0less-build.c | 43 +++++++++++++++++++++++++
xen/arch/arm/domain_build.c | 30 ++++++++++-------
xen/arch/arm/include/asm/domain_build.h | 2 ++
3 files changed, 64 insertions(+), 11 deletions(-)
diff --git a/xen/arch/arm/dom0less-build.c b/xen/arch/arm/dom0less-build.c
index 1e1c8d83ae..99447bfb0c 100644
--- a/xen/arch/arm/dom0less-build.c
+++ b/xen/arch/arm/dom0less-build.c
@@ -682,6 +682,49 @@ static int __init prepare_dtb_domU(struct domain *d,
struct kernel_info *kinfo)
if ( kinfo->dom0less_feature & DOM0LESS_ENHANCED_NO_XS )
{
+ if ( is_domain_direct_mapped(d) )
+ {
+ struct meminfo *avail_magic_regions = xzalloc(struct meminfo);
+ struct meminfo *rsrv_mem = &bootinfo.reserved_mem;
+ struct mem_map_domain *mem_map = &d->arch.mem_map;
+ uint64_t magic_region_start = INVALID_PADDR;
+ uint64_t magic_region_size = GUEST_MAGIC_SIZE;
+ unsigned int i;
+
+ if ( !avail_magic_regions )
+ return -ENOMEM;
+
+ ret = find_unused_memory(d, kinfo, avail_magic_regions);
+ if ( ret )
+ {
+ printk(XENLOG_WARNING
+ "%pd: failed to find a region for domain magic pages\n",
+ d);
+ goto err;
+ }
+
+ magic_region_start = avail_magic_regions->bank[0].start;
+
+ /*
+ * Register the magic region as reserved mem to make sure this
+ * region will not be counted when allocating extended regions.
+ */
+ rsrv_mem->bank[rsrv_mem->nr_banks].start = magic_region_start;
+ rsrv_mem->bank[rsrv_mem->nr_banks].size = magic_region_size;
+ rsrv_mem->bank[rsrv_mem->nr_banks].type = MEMBANK_DEFAULT;
+ rsrv_mem->nr_banks++;
+
+ /* Update the domain memory map. */
+ for ( i = 0; i < mem_map->nr_mem_regions; i++ )
+ {
+ if ( mem_map->regions[i].type == GUEST_MEM_REGION_MAGIC )
+ {
+ mem_map->regions[i].start = magic_region_start;
+ mem_map->regions[i].size = magic_region_size;
+ }
+ }
+ }
+
ret = make_hypervisor_node(d, kinfo, addrcells, sizecells);
if ( ret )
goto err;
diff --git a/xen/arch/arm/domain_build.c b/xen/arch/arm/domain_build.c
index 085d88671e..b36b98ee7d 100644
--- a/xen/arch/arm/domain_build.c
+++ b/xen/arch/arm/domain_build.c
@@ -1110,6 +1110,24 @@ static int __init find_domU_holes(const struct
kernel_info *kinfo,
return res;
}
+int __init find_unused_memory(struct domain *d, const struct kernel_info
*kinfo,
+ struct meminfo *mem_region)
+{
+ int res;
+
+ if ( is_domain_direct_mapped(d) )
+ {
+ if ( !is_iommu_enabled(d) )
+ res = find_unallocated_memory(kinfo, mem_region);
+ else
+ res = find_memory_holes(kinfo, mem_region);
+ }
+ else
+ res = find_domU_holes(kinfo, mem_region);
+
+ return res;
+}
+
int __init make_hypervisor_node(struct domain *d,
const struct kernel_info *kinfo,
int addrcells, int sizecells)
@@ -1161,17 +1179,7 @@ int __init make_hypervisor_node(struct domain *d,
if ( !ext_regions )
return -ENOMEM;
- if ( is_domain_direct_mapped(d) )
- {
- if ( !is_iommu_enabled(d) )
- res = find_unallocated_memory(kinfo, ext_regions);
- else
- res = find_memory_holes(kinfo, ext_regions);
- }
- else
- {
- res = find_domU_holes(kinfo, ext_regions);
- }
+ res = find_unused_memory(d, kinfo, ext_regions);
if ( res )
printk(XENLOG_WARNING "%pd: failed to allocate extended regions\n",
diff --git a/xen/arch/arm/include/asm/domain_build.h
b/xen/arch/arm/include/asm/domain_build.h
index da9e6025f3..4458012644 100644
--- a/xen/arch/arm/include/asm/domain_build.h
+++ b/xen/arch/arm/include/asm/domain_build.h
@@ -10,6 +10,8 @@ bool allocate_bank_memory(struct domain *d, struct
kernel_info *kinfo,
gfn_t sgfn, paddr_t tot_size);
int construct_domain(struct domain *d, struct kernel_info *kinfo);
int domain_fdt_begin_node(void *fdt, const char *name, uint64_t unit);
+int find_unused_memory(struct domain *d, const struct kernel_info *kinfo,
+ struct meminfo *mem_region);
int make_chosen_node(const struct kernel_info *kinfo);
int make_cpus_node(const struct domain *d, void *fdt);
int make_hypervisor_node(struct domain *d, const struct kernel_info *kinfo,
--
2.34.1
