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[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] [Xen-changelog] [xen master] xen/arm: Add relinquish_p2m_mapping to remove reference on every mapped page
commit 84f29a98dc31fcf4a6bbf380601f4b3651c761f8
Author: Julien Grall <julien.grall@xxxxxxxxxx>
AuthorDate: Tue Dec 17 16:27:56 2013 +0000
Commit: Ian Campbell <ian.campbell@xxxxxxxxxx>
CommitDate: Wed Dec 18 14:32:48 2013 +0000
xen/arm: Add relinquish_p2m_mapping to remove reference on every mapped page
This function will be called when the domain relinquishes its memory.
It removes refcount on every mapped page to a valid MFN.
Currently, Xen doesn't take reference on every new mapping but only for
foreign
mapping. Restrict the function only on foreign mapping.
Signed-off-by: Julien Grall <julien.grall@xxxxxxxxxx>
Acked-by: Ian Campbell <ian.campbell@xxxxxxxxxx>
---
xen/arch/arm/domain.c | 8 ++++++
xen/arch/arm/p2m.c | 49 +++++++++++++++++++++++++++++++++++++++++-
xen/include/asm-arm/domain.h | 1 +
xen/include/asm-arm/p2m.h | 15 ++++++++++++
4 files changed, 72 insertions(+), 1 deletions(-)
diff --git a/xen/arch/arm/domain.c b/xen/arch/arm/domain.c
index 1590708..4099e88 100644
--- a/xen/arch/arm/domain.c
+++ b/xen/arch/arm/domain.c
@@ -717,6 +717,14 @@ int domain_relinquish_resources(struct domain *d)
if ( ret )
return ret;
+ d->arch.relmem = RELMEM_mapping;
+ /* Fallthrough */
+
+ case RELMEM_mapping:
+ ret = relinquish_p2m_mapping(d);
+ if ( ret )
+ return ret;
+
d->arch.relmem = RELMEM_done;
/* Fallthrough */
diff --git a/xen/arch/arm/p2m.c b/xen/arch/arm/p2m.c
index 410acb6..3f4ab37 100644
--- a/xen/arch/arm/p2m.c
+++ b/xen/arch/arm/p2m.c
@@ -6,6 +6,8 @@
#include <xen/bitops.h>
#include <asm/flushtlb.h>
#include <asm/gic.h>
+#include <asm/event.h>
+#include <asm/hardirq.h>
/* First level P2M is 2 consecutive pages */
#define P2M_FIRST_ORDER 1
@@ -224,7 +226,8 @@ static int p2m_create_table(struct domain *d,
enum p2m_operation {
INSERT,
ALLOCATE,
- REMOVE
+ REMOVE,
+ RELINQUISH,
};
static int create_p2m_entries(struct domain *d,
@@ -242,6 +245,7 @@ static int create_p2m_entries(struct domain *d,
unsigned long cur_first_page = ~0,
cur_first_offset = ~0,
cur_second_offset = ~0;
+ unsigned long count = 0;
spin_lock(&p2m->lock);
@@ -326,13 +330,19 @@ static int create_p2m_entries(struct domain *d,
maddr += PAGE_SIZE;
}
break;
+ case RELINQUISH:
case REMOVE:
{
lpae_t pte = third[third_table_offset(addr)];
unsigned long mfn = pte.p2m.base;
if ( !pte.p2m.valid )
+ {
+ count++;
break;
+ }
+
+ count += 0x10;
/* TODO: Handle other p2m type */
if ( p2m_is_foreign(pte.p2m.type) )
@@ -343,12 +353,35 @@ static int create_p2m_entries(struct domain *d,
memset(&pte, 0x00, sizeof(pte));
write_pte(&third[third_table_offset(addr)], pte);
+ count++;
}
break;
}
if ( flush )
flush_tlb_all_local();
+
+ /* Preempt every 2MiB (mapped) or 32 MiB (unmapped) - arbitrary */
+ if ( op == RELINQUISH && count >= 0x2000 )
+ {
+ if ( hypercall_preempt_check() )
+ {
+ p2m->next_gfn_to_relinquish = maddr >> PAGE_SHIFT;
+ rc = -EAGAIN;
+ goto out;
+ }
+ count = 0;
+ }
+ }
+
+ if ( op == ALLOCATE || op == INSERT )
+ {
+ unsigned long sgfn = paddr_to_pfn(start_gpaddr);
+ unsigned long egfn = paddr_to_pfn(end_gpaddr);
+
+ p2m->max_mapped_gfn = MAX(p2m->max_mapped_gfn, egfn);
+ /* Use next_gfn_to_relinquish to store the lowest gfn mapped */
+ p2m->next_gfn_to_relinquish = MIN(p2m->next_gfn_to_relinquish, sgfn);
}
rc = 0;
@@ -534,12 +567,26 @@ int p2m_init(struct domain *d)
p2m->first_level = NULL;
+ p2m->max_mapped_gfn = 0;
+ p2m->next_gfn_to_relinquish = ULONG_MAX;
+
err:
spin_unlock(&p2m->lock);
return rc;
}
+int relinquish_p2m_mapping(struct domain *d)
+{
+ struct p2m_domain *p2m = &d->arch.p2m;
+
+ return create_p2m_entries(d, RELINQUISH,
+ pfn_to_paddr(p2m->next_gfn_to_relinquish),
+ pfn_to_paddr(p2m->max_mapped_gfn),
+ pfn_to_paddr(INVALID_MFN),
+ MATTR_MEM, p2m_invalid);
+}
+
unsigned long gmfn_to_mfn(struct domain *d, unsigned long gpfn)
{
paddr_t p = p2m_lookup(d, pfn_to_paddr(gpfn), NULL);
diff --git a/xen/include/asm-arm/domain.h b/xen/include/asm-arm/domain.h
index 53c9895..28d39a0 100644
--- a/xen/include/asm-arm/domain.h
+++ b/xen/include/asm-arm/domain.h
@@ -112,6 +112,7 @@ struct arch_domain
RELMEM_not_started,
RELMEM_xen,
RELMEM_page,
+ RELMEM_mapping,
RELMEM_done,
} relmem;
diff --git a/xen/include/asm-arm/p2m.h b/xen/include/asm-arm/p2m.h
index 5ccfa7f..8b7b6d0 100644
--- a/xen/include/asm-arm/p2m.h
+++ b/xen/include/asm-arm/p2m.h
@@ -18,6 +18,15 @@ struct p2m_domain {
/* Current VMID in use */
uint8_t vmid;
+
+ /* Highest guest frame that's ever been mapped in the p2m
+ * Only takes into account ram and foreign mapping
+ */
+ unsigned long max_mapped_gfn;
+
+ /* When releasing mapped gfn's in a preemptible manner, recall where
+ * to resume the search */
+ unsigned long next_gfn_to_relinquish;
};
/* List of possible type for each page in the p2m entry.
@@ -48,6 +57,12 @@ int p2m_init(struct domain *d);
/* Return all the p2m resources to Xen. */
void p2m_teardown(struct domain *d);
+/* Remove mapping refcount on each mapping page in the p2m
+ *
+ * TODO: For the moment only foreign mappings are handled
+ */
+int relinquish_p2m_mapping(struct domain *d);
+
/* Allocate a new p2m table for a domain.
*
* Returns 0 for success or -errno.
--
generated by git-patchbot for /home/xen/git/xen.git#master
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