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xen: use correct cache attributes for Xen specific memory regions

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bus_activate_resource maps memory regions as uncacheable on x86, which
is more strict than required for regions allocated using xenmem_alloc,
so don't rely on bus_activate_resource and instead map the region
using pmap_mapdev_attr and VM_MEMATTR_XEN as the cache attribute.

Sponsored by: Citrix Systems R&D
This commit is contained in:
Roger Pau Monné 2021-04-09 11:31:44 +02:00
parent 080c6fdc0c
commit f4c6843ec2
1 changed files with 8 additions and 1 deletions
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9
sys/dev/xen/bus/xenpv.c
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@ -120,10 +120,11 @@ xenpv_alloc_physmem(device_t dev, device_t child, int *res_id, size_t size)
{
struct resource *res;
vm_paddr_t phys_addr;
void *virt_addr;
int error;
res = bus_alloc_resource(child, SYS_RES_MEMORY, res_id, LOW_MEM_LIMIT,
~0, size, RF_ACTIVE);
~0, size, RF_ACTIVE | RF_UNMAPPED);
if (res == NULL)
return (NULL);
@ -134,6 +135,9 @@ xenpv_alloc_physmem(device_t dev, device_t child, int *res_id, size_t size)
bus_release_resource(child, SYS_RES_MEMORY, *res_id, res);
return (NULL);
}
virt_addr = pmap_mapdev_attr(phys_addr, size, VM_MEMATTR_XEN);
KASSERT(virt_addr != NULL, ("Failed to create linear mappings"));
rman_set_virtual(res, virt_addr);
return (res);
}
@ -142,11 +146,14 @@ static int
xenpv_free_physmem(device_t dev, device_t child, int res_id, struct resource *res)
{
vm_paddr_t phys_addr;
vm_offset_t virt_addr;
size_t size;
phys_addr = rman_get_start(res);
size = rman_get_size(res);
virt_addr = (vm_offset_t)rman_get_virtual(res);
pmap_unmapdev(virt_addr, size);
vm_phys_fictitious_unreg_range(phys_addr, phys_addr + size);
return (bus_release_resource(child, SYS_RES_MEMORY, res_id, res));
}