* [PULL 1/5] xen: mapcache: Make MCACHE_BUCKET_SHIFT runtime configurable
2024-06-12 21:29 [PULL 0/5] virtio-grants-v8-tag Stefano Stabellini
@ 2024-06-12 21:29 ` Stefano Stabellini
2024-06-12 21:29 ` [PULL 2/5] xen: mapcache: Unmap first entries in buckets Stefano Stabellini
` (5 subsequent siblings)
6 siblings, 0 replies; 9+ messages in thread
From: Stefano Stabellini @ 2024-06-12 21:29 UTC (permalink / raw)
To: qemu-devel
Cc: stefanha, peter.maydell, sstabellini, Edgar.Iglesias,
Edgar E. Iglesias, Philippe Mathieu-Daudé
From: "Edgar E. Iglesias" <edgar.iglesias@amd.com>
Make MCACHE_BUCKET_SHIFT runtime configurable per cache instance.
Signed-off-by: Edgar E. Iglesias <edgar.iglesias@amd.com>
Reviewed-by: Stefano Stabellini <sstabellini@kernel.org>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
---
hw/xen/xen-mapcache.c | 54 ++++++++++++++++++++++++++-----------------
1 file changed, 33 insertions(+), 21 deletions(-)
diff --git a/hw/xen/xen-mapcache.c b/hw/xen/xen-mapcache.c
index fa6813b1ad..bc860f4373 100644
--- a/hw/xen/xen-mapcache.c
+++ b/hw/xen/xen-mapcache.c
@@ -23,13 +23,10 @@
#if HOST_LONG_BITS == 32
-# define MCACHE_BUCKET_SHIFT 16
# define MCACHE_MAX_SIZE (1UL<<31) /* 2GB Cap */
#else
-# define MCACHE_BUCKET_SHIFT 20
# define MCACHE_MAX_SIZE (1UL<<35) /* 32GB Cap */
#endif
-#define MCACHE_BUCKET_SIZE (1UL << MCACHE_BUCKET_SHIFT)
/* This is the size of the virtual address space reserve to QEMU that will not
* be use by MapCache.
@@ -65,7 +62,8 @@ typedef struct MapCache {
/* For most cases (>99.9%), the page address is the same. */
MapCacheEntry *last_entry;
unsigned long max_mcache_size;
- unsigned int mcache_bucket_shift;
+ unsigned int bucket_shift;
+ unsigned long bucket_size;
phys_offset_to_gaddr_t phys_offset_to_gaddr;
QemuMutex lock;
@@ -95,11 +93,14 @@ static inline int test_bits(int nr, int size, const unsigned long *addr)
static MapCache *xen_map_cache_init_single(phys_offset_to_gaddr_t f,
void *opaque,
+ unsigned int bucket_shift,
unsigned long max_size)
{
unsigned long size;
MapCache *mc;
+ assert(bucket_shift >= XC_PAGE_SHIFT);
+
mc = g_new0(MapCache, 1);
mc->phys_offset_to_gaddr = f;
@@ -108,12 +109,14 @@ static MapCache *xen_map_cache_init_single(phys_offset_to_gaddr_t f,
QTAILQ_INIT(&mc->locked_entries);
+ mc->bucket_shift = bucket_shift;
+ mc->bucket_size = 1UL << bucket_shift;
mc->max_mcache_size = max_size;
mc->nr_buckets =
(((mc->max_mcache_size >> XC_PAGE_SHIFT) +
- (1UL << (MCACHE_BUCKET_SHIFT - XC_PAGE_SHIFT)) - 1) >>
- (MCACHE_BUCKET_SHIFT - XC_PAGE_SHIFT));
+ (1UL << (bucket_shift - XC_PAGE_SHIFT)) - 1) >>
+ (bucket_shift - XC_PAGE_SHIFT));
size = mc->nr_buckets * sizeof(MapCacheEntry);
size = (size + XC_PAGE_SIZE - 1) & ~(XC_PAGE_SIZE - 1);
@@ -126,6 +129,13 @@ void xen_map_cache_init(phys_offset_to_gaddr_t f, void *opaque)
{
struct rlimit rlimit_as;
unsigned long max_mcache_size;
+ unsigned int bucket_shift;
+
+ if (HOST_LONG_BITS == 32) {
+ bucket_shift = 16;
+ } else {
+ bucket_shift = 20;
+ }
if (geteuid() == 0) {
rlimit_as.rlim_cur = RLIM_INFINITY;
@@ -146,7 +156,9 @@ void xen_map_cache_init(phys_offset_to_gaddr_t f, void *opaque)
}
}
- mapcache = xen_map_cache_init_single(f, opaque, max_mcache_size);
+ mapcache = xen_map_cache_init_single(f, opaque,
+ bucket_shift,
+ max_mcache_size);
setrlimit(RLIMIT_AS, &rlimit_as);
}
@@ -195,7 +207,7 @@ static void xen_remap_bucket(MapCache *mc,
entry->valid_mapping = NULL;
for (i = 0; i < nb_pfn; i++) {
- pfns[i] = (address_index << (MCACHE_BUCKET_SHIFT-XC_PAGE_SHIFT)) + i;
+ pfns[i] = (address_index << (mc->bucket_shift - XC_PAGE_SHIFT)) + i;
}
/*
@@ -266,8 +278,8 @@ static uint8_t *xen_map_cache_unlocked(MapCache *mc,
bool dummy = false;
tryagain:
- address_index = phys_addr >> MCACHE_BUCKET_SHIFT;
- address_offset = phys_addr & (MCACHE_BUCKET_SIZE - 1);
+ address_index = phys_addr >> mc->bucket_shift;
+ address_offset = phys_addr & (mc->bucket_size - 1);
trace_xen_map_cache(phys_addr);
@@ -294,14 +306,14 @@ tryagain:
return mc->last_entry->vaddr_base + address_offset;
}
- /* size is always a multiple of MCACHE_BUCKET_SIZE */
+ /* size is always a multiple of mc->bucket_size */
if (size) {
cache_size = size + address_offset;
- if (cache_size % MCACHE_BUCKET_SIZE) {
- cache_size += MCACHE_BUCKET_SIZE - (cache_size % MCACHE_BUCKET_SIZE);
+ if (cache_size % mc->bucket_size) {
+ cache_size += mc->bucket_size - (cache_size % mc->bucket_size);
}
} else {
- cache_size = MCACHE_BUCKET_SIZE;
+ cache_size = mc->bucket_size;
}
entry = &mc->entry[address_index % mc->nr_buckets];
@@ -422,7 +434,7 @@ static ram_addr_t xen_ram_addr_from_mapcache_single(MapCache *mc, void *ptr)
trace_xen_ram_addr_from_mapcache_not_in_cache(ptr);
raddr = RAM_ADDR_INVALID;
} else {
- raddr = (reventry->paddr_index << MCACHE_BUCKET_SHIFT) +
+ raddr = (reventry->paddr_index << mc->bucket_shift) +
((unsigned long) ptr - (unsigned long) entry->vaddr_base);
}
mapcache_unlock(mc);
@@ -585,8 +597,8 @@ static uint8_t *xen_replace_cache_entry_unlocked(MapCache *mc,
hwaddr address_index, address_offset;
hwaddr test_bit_size, cache_size = size;
- address_index = old_phys_addr >> MCACHE_BUCKET_SHIFT;
- address_offset = old_phys_addr & (MCACHE_BUCKET_SIZE - 1);
+ address_index = old_phys_addr >> mc->bucket_shift;
+ address_offset = old_phys_addr & (mc->bucket_size - 1);
assert(size);
/* test_bit_size is always a multiple of XC_PAGE_SIZE */
@@ -595,8 +607,8 @@ static uint8_t *xen_replace_cache_entry_unlocked(MapCache *mc,
test_bit_size += XC_PAGE_SIZE - (test_bit_size % XC_PAGE_SIZE);
}
cache_size = size + address_offset;
- if (cache_size % MCACHE_BUCKET_SIZE) {
- cache_size += MCACHE_BUCKET_SIZE - (cache_size % MCACHE_BUCKET_SIZE);
+ if (cache_size % mc->bucket_size) {
+ cache_size += mc->bucket_size - (cache_size % mc->bucket_size);
}
entry = &mc->entry[address_index % mc->nr_buckets];
@@ -609,8 +621,8 @@ static uint8_t *xen_replace_cache_entry_unlocked(MapCache *mc,
return NULL;
}
- address_index = new_phys_addr >> MCACHE_BUCKET_SHIFT;
- address_offset = new_phys_addr & (MCACHE_BUCKET_SIZE - 1);
+ address_index = new_phys_addr >> mc->bucket_shift;
+ address_offset = new_phys_addr & (mc->bucket_size - 1);
trace_xen_replace_cache_entry_dummy(old_phys_addr, new_phys_addr);
--
2.25.1
^ permalink raw reply related [flat|nested] 9+ messages in thread* [PULL 2/5] xen: mapcache: Unmap first entries in buckets
2024-06-12 21:29 [PULL 0/5] virtio-grants-v8-tag Stefano Stabellini
2024-06-12 21:29 ` [PULL 1/5] xen: mapcache: Make MCACHE_BUCKET_SHIFT runtime configurable Stefano Stabellini
@ 2024-06-12 21:29 ` Stefano Stabellini
2024-06-12 21:29 ` [PULL 3/5] xen: mapcache: Pass the ram_addr offset to xen_map_cache() Stefano Stabellini
` (4 subsequent siblings)
6 siblings, 0 replies; 9+ messages in thread
From: Stefano Stabellini @ 2024-06-12 21:29 UTC (permalink / raw)
To: qemu-devel
Cc: stefanha, peter.maydell, sstabellini, Edgar.Iglesias,
Edgar E. Iglesias
From: "Edgar E. Iglesias" <edgar.iglesias@amd.com>
When invalidating memory ranges, if we happen to hit the first
entry in a bucket we were never unmapping it. This was harmless
for foreign mappings but now that we're looking to reuse the
mapcache for transient grant mappings, we must unmap entries
when invalidated.
Signed-off-by: Edgar E. Iglesias <edgar.iglesias@amd.com>
Reviewed-by: Stefano Stabellini <sstabellini@kernel.org>
---
hw/xen/xen-mapcache.c | 11 ++++++++---
1 file changed, 8 insertions(+), 3 deletions(-)
diff --git a/hw/xen/xen-mapcache.c b/hw/xen/xen-mapcache.c
index bc860f4373..ec95445696 100644
--- a/hw/xen/xen-mapcache.c
+++ b/hw/xen/xen-mapcache.c
@@ -491,18 +491,23 @@ static void xen_invalidate_map_cache_entry_unlocked(MapCache *mc,
return;
}
entry->lock--;
- if (entry->lock > 0 || pentry == NULL) {
+ if (entry->lock > 0) {
return;
}
- pentry->next = entry->next;
ram_block_notify_remove(entry->vaddr_base, entry->size, entry->size);
if (munmap(entry->vaddr_base, entry->size) != 0) {
perror("unmap fails");
exit(-1);
}
+
g_free(entry->valid_mapping);
- g_free(entry);
+ if (pentry) {
+ pentry->next = entry->next;
+ g_free(entry);
+ } else {
+ memset(entry, 0, sizeof *entry);
+ }
}
typedef struct XenMapCacheData {
--
2.25.1
^ permalink raw reply related [flat|nested] 9+ messages in thread* [PULL 3/5] xen: mapcache: Pass the ram_addr offset to xen_map_cache()
2024-06-12 21:29 [PULL 0/5] virtio-grants-v8-tag Stefano Stabellini
2024-06-12 21:29 ` [PULL 1/5] xen: mapcache: Make MCACHE_BUCKET_SHIFT runtime configurable Stefano Stabellini
2024-06-12 21:29 ` [PULL 2/5] xen: mapcache: Unmap first entries in buckets Stefano Stabellini
@ 2024-06-12 21:29 ` Stefano Stabellini
2024-06-12 21:29 ` [PULL 4/5] xen: mapcache: Add support for grant mappings Stefano Stabellini
` (3 subsequent siblings)
6 siblings, 0 replies; 9+ messages in thread
From: Stefano Stabellini @ 2024-06-12 21:29 UTC (permalink / raw)
To: qemu-devel
Cc: stefanha, peter.maydell, sstabellini, Edgar.Iglesias,
Edgar E. Iglesias, David Hildenbrand, Philippe Mathieu-Daudé
From: "Edgar E. Iglesias" <edgar.iglesias@amd.com>
Pass the ram_addr offset to xen_map_cache.
This is in preparation for adding grant mappings that need
to compute the address within the RAMBlock.
No functional changes.
Signed-off-by: Edgar E. Iglesias <edgar.iglesias@amd.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Stefano Stabellini <sstabellini@kernel.org>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
---
hw/xen/xen-mapcache.c | 16 +++++++++++-----
include/sysemu/xen-mapcache.h | 2 ++
system/physmem.c | 9 +++++----
3 files changed, 18 insertions(+), 9 deletions(-)
diff --git a/hw/xen/xen-mapcache.c b/hw/xen/xen-mapcache.c
index ec95445696..a07c47b0b1 100644
--- a/hw/xen/xen-mapcache.c
+++ b/hw/xen/xen-mapcache.c
@@ -167,7 +167,8 @@ static void xen_remap_bucket(MapCache *mc,
void *vaddr,
hwaddr size,
hwaddr address_index,
- bool dummy)
+ bool dummy,
+ ram_addr_t ram_offset)
{
uint8_t *vaddr_base;
xen_pfn_t *pfns;
@@ -266,6 +267,7 @@ static void xen_remap_bucket(MapCache *mc,
static uint8_t *xen_map_cache_unlocked(MapCache *mc,
hwaddr phys_addr, hwaddr size,
+ ram_addr_t ram_offset,
uint8_t lock, bool dma, bool is_write)
{
MapCacheEntry *entry, *pentry = NULL,
@@ -337,14 +339,16 @@ tryagain:
if (!entry) {
entry = g_new0(MapCacheEntry, 1);
pentry->next = entry;
- xen_remap_bucket(mc, entry, NULL, cache_size, address_index, dummy);
+ xen_remap_bucket(mc, entry, NULL, cache_size, address_index, dummy,
+ ram_offset);
} else if (!entry->lock) {
if (!entry->vaddr_base || entry->paddr_index != address_index ||
entry->size != cache_size ||
!test_bits(address_offset >> XC_PAGE_SHIFT,
test_bit_size >> XC_PAGE_SHIFT,
entry->valid_mapping)) {
- xen_remap_bucket(mc, entry, NULL, cache_size, address_index, dummy);
+ xen_remap_bucket(mc, entry, NULL, cache_size, address_index, dummy,
+ ram_offset);
}
}
@@ -391,13 +395,15 @@ tryagain:
uint8_t *xen_map_cache(MemoryRegion *mr,
hwaddr phys_addr, hwaddr size,
+ ram_addr_t ram_addr_offset,
uint8_t lock, bool dma,
bool is_write)
{
uint8_t *p;
mapcache_lock(mapcache);
- p = xen_map_cache_unlocked(mapcache, phys_addr, size, lock, dma, is_write);
+ p = xen_map_cache_unlocked(mapcache, phys_addr, size, ram_addr_offset,
+ lock, dma, is_write);
mapcache_unlock(mapcache);
return p;
}
@@ -632,7 +638,7 @@ static uint8_t *xen_replace_cache_entry_unlocked(MapCache *mc,
trace_xen_replace_cache_entry_dummy(old_phys_addr, new_phys_addr);
xen_remap_bucket(mc, entry, entry->vaddr_base,
- cache_size, address_index, false);
+ cache_size, address_index, false, old_phys_addr);
if (!test_bits(address_offset >> XC_PAGE_SHIFT,
test_bit_size >> XC_PAGE_SHIFT,
entry->valid_mapping)) {
diff --git a/include/sysemu/xen-mapcache.h b/include/sysemu/xen-mapcache.h
index 1ec9e66752..b5e3ea1bc0 100644
--- a/include/sysemu/xen-mapcache.h
+++ b/include/sysemu/xen-mapcache.h
@@ -19,6 +19,7 @@ typedef hwaddr (*phys_offset_to_gaddr_t)(hwaddr phys_offset,
void xen_map_cache_init(phys_offset_to_gaddr_t f,
void *opaque);
uint8_t *xen_map_cache(MemoryRegion *mr, hwaddr phys_addr, hwaddr size,
+ ram_addr_t ram_addr_offset,
uint8_t lock, bool dma,
bool is_write);
ram_addr_t xen_ram_addr_from_mapcache(void *ptr);
@@ -37,6 +38,7 @@ static inline void xen_map_cache_init(phys_offset_to_gaddr_t f,
static inline uint8_t *xen_map_cache(MemoryRegion *mr,
hwaddr phys_addr,
hwaddr size,
+ ram_addr_t ram_addr_offset,
uint8_t lock,
bool dma,
bool is_write)
diff --git a/system/physmem.c b/system/physmem.c
index b7847db1a2..33d09f7571 100644
--- a/system/physmem.c
+++ b/system/physmem.c
@@ -2231,13 +2231,14 @@ static void *qemu_ram_ptr_length(RAMBlock *block, ram_addr_t addr,
*/
if (xen_mr_is_memory(block->mr)) {
return xen_map_cache(block->mr, block->offset + addr,
- len, lock, lock,
- is_write);
+ len, block->offset,
+ lock, lock, is_write);
}
block->host = xen_map_cache(block->mr, block->offset,
- block->max_length, 1,
- lock, is_write);
+ block->max_length,
+ block->offset,
+ 1, lock, is_write);
}
return ramblock_ptr(block, addr);
--
2.25.1
^ permalink raw reply related [flat|nested] 9+ messages in thread* [PULL 4/5] xen: mapcache: Add support for grant mappings
2024-06-12 21:29 [PULL 0/5] virtio-grants-v8-tag Stefano Stabellini
` (2 preceding siblings ...)
2024-06-12 21:29 ` [PULL 3/5] xen: mapcache: Pass the ram_addr offset to xen_map_cache() Stefano Stabellini
@ 2024-06-12 21:29 ` Stefano Stabellini
2024-06-12 21:29 ` [PULL 5/5] hw/arm: xen: Enable use of " Stefano Stabellini
` (2 subsequent siblings)
6 siblings, 0 replies; 9+ messages in thread
From: Stefano Stabellini @ 2024-06-12 21:29 UTC (permalink / raw)
To: qemu-devel
Cc: stefanha, peter.maydell, sstabellini, Edgar.Iglesias,
Edgar E. Iglesias, Manos Pitsidianakis
From: "Edgar E. Iglesias" <edgar.iglesias@amd.com>
Add a second mapcache for grant mappings. The mapcache for
grants needs to work with XC_PAGE_SIZE granularity since
we can't map larger ranges than what has been granted to us.
Like with foreign mappings (xen_memory), machines using grants
are expected to initialize the xen_grants MR and map it
into their address-map accordingly.
CC: Manos Pitsidianakis <manos.pitsidianakis@linaro.org>
Signed-off-by: Edgar E. Iglesias <edgar.iglesias@amd.com>
Reviewed-by: Stefano Stabellini <sstabellini@kernel.org>
---
hw/xen/xen-hvm-common.c | 12 ++-
hw/xen/xen-mapcache.c | 165 +++++++++++++++++++++++++-------
include/hw/xen/xen-hvm-common.h | 3 +
include/sysemu/xen.h | 1 +
4 files changed, 144 insertions(+), 37 deletions(-)
diff --git a/hw/xen/xen-hvm-common.c b/hw/xen/xen-hvm-common.c
index a0a0252da0..b8ace1c368 100644
--- a/hw/xen/xen-hvm-common.c
+++ b/hw/xen/xen-hvm-common.c
@@ -10,12 +10,18 @@
#include "hw/boards.h"
#include "hw/xen/arch_hvm.h"
-MemoryRegion xen_memory;
+MemoryRegion xen_memory, xen_grants;
-/* Check for xen memory. */
+/* Check for any kind of xen memory, foreign mappings or grants. */
bool xen_mr_is_memory(MemoryRegion *mr)
{
- return mr == &xen_memory;
+ return mr == &xen_memory || mr == &xen_grants;
+}
+
+/* Check specifically for grants. */
+bool xen_mr_is_grants(MemoryRegion *mr)
+{
+ return mr == &xen_grants;
}
void xen_ram_alloc(ram_addr_t ram_addr, ram_addr_t size, MemoryRegion *mr,
diff --git a/hw/xen/xen-mapcache.c b/hw/xen/xen-mapcache.c
index a07c47b0b1..5f23b0adbe 100644
--- a/hw/xen/xen-mapcache.c
+++ b/hw/xen/xen-mapcache.c
@@ -14,6 +14,7 @@
#include <sys/resource.h>
+#include "hw/xen/xen-hvm-common.h"
#include "hw/xen/xen_native.h"
#include "qemu/bitmap.h"
@@ -21,6 +22,8 @@
#include "sysemu/xen-mapcache.h"
#include "trace.h"
+#include <xenevtchn.h>
+#include <xengnttab.h>
#if HOST_LONG_BITS == 32
# define MCACHE_MAX_SIZE (1UL<<31) /* 2GB Cap */
@@ -41,6 +44,7 @@ typedef struct MapCacheEntry {
unsigned long *valid_mapping;
uint32_t lock;
#define XEN_MAPCACHE_ENTRY_DUMMY (1 << 0)
+#define XEN_MAPCACHE_ENTRY_GRANT (1 << 1)
uint8_t flags;
hwaddr size;
struct MapCacheEntry *next;
@@ -71,6 +75,8 @@ typedef struct MapCache {
} MapCache;
static MapCache *mapcache;
+static MapCache *mapcache_grants;
+static xengnttab_handle *xen_region_gnttabdev;
static inline void mapcache_lock(MapCache *mc)
{
@@ -131,6 +137,12 @@ void xen_map_cache_init(phys_offset_to_gaddr_t f, void *opaque)
unsigned long max_mcache_size;
unsigned int bucket_shift;
+ xen_region_gnttabdev = xengnttab_open(NULL, 0);
+ if (xen_region_gnttabdev == NULL) {
+ error_report("mapcache: Failed to open gnttab device");
+ exit(EXIT_FAILURE);
+ }
+
if (HOST_LONG_BITS == 32) {
bucket_shift = 16;
} else {
@@ -159,6 +171,15 @@ void xen_map_cache_init(phys_offset_to_gaddr_t f, void *opaque)
mapcache = xen_map_cache_init_single(f, opaque,
bucket_shift,
max_mcache_size);
+
+ /*
+ * Grant mappings must use XC_PAGE_SIZE granularity since we can't
+ * map anything beyond the number of pages granted to us.
+ */
+ mapcache_grants = xen_map_cache_init_single(f, opaque,
+ XC_PAGE_SHIFT,
+ max_mcache_size);
+
setrlimit(RLIMIT_AS, &rlimit_as);
}
@@ -168,17 +189,24 @@ static void xen_remap_bucket(MapCache *mc,
hwaddr size,
hwaddr address_index,
bool dummy,
+ bool grant,
+ bool is_write,
ram_addr_t ram_offset)
{
uint8_t *vaddr_base;
- xen_pfn_t *pfns;
- int *err;
+ g_autofree uint32_t *refs = NULL;
+ g_autofree xen_pfn_t *pfns = NULL;
+ g_autofree int *err;
unsigned int i;
hwaddr nb_pfn = size >> XC_PAGE_SHIFT;
trace_xen_remap_bucket(address_index);
- pfns = g_new0(xen_pfn_t, nb_pfn);
+ if (grant) {
+ refs = g_new0(uint32_t, nb_pfn);
+ } else {
+ pfns = g_new0(xen_pfn_t, nb_pfn);
+ }
err = g_new0(int, nb_pfn);
if (entry->vaddr_base != NULL) {
@@ -207,21 +235,51 @@ static void xen_remap_bucket(MapCache *mc,
g_free(entry->valid_mapping);
entry->valid_mapping = NULL;
- for (i = 0; i < nb_pfn; i++) {
- pfns[i] = (address_index << (mc->bucket_shift - XC_PAGE_SHIFT)) + i;
+ if (grant) {
+ hwaddr grant_base = address_index - (ram_offset >> XC_PAGE_SHIFT);
+
+ for (i = 0; i < nb_pfn; i++) {
+ refs[i] = grant_base + i;
+ }
+ } else {
+ for (i = 0; i < nb_pfn; i++) {
+ pfns[i] = (address_index << (mc->bucket_shift - XC_PAGE_SHIFT)) + i;
+ }
}
- /*
- * If the caller has requested the mapping at a specific address use
- * MAP_FIXED to make sure it's honored.
- */
+ entry->flags &= ~XEN_MAPCACHE_ENTRY_GRANT;
+
if (!dummy) {
- vaddr_base = xenforeignmemory_map2(xen_fmem, xen_domid, vaddr,
- PROT_READ | PROT_WRITE,
- vaddr ? MAP_FIXED : 0,
- nb_pfn, pfns, err);
+ if (grant) {
+ int prot = PROT_READ;
+
+ if (is_write) {
+ prot |= PROT_WRITE;
+ }
+
+ entry->flags |= XEN_MAPCACHE_ENTRY_GRANT;
+ assert(vaddr == NULL);
+ vaddr_base = xengnttab_map_domain_grant_refs(xen_region_gnttabdev,
+ nb_pfn,
+ xen_domid, refs,
+ prot);
+ } else {
+ /*
+ * If the caller has requested the mapping at a specific address use
+ * MAP_FIXED to make sure it's honored.
+ *
+ * We don't yet support upgrading mappings from RO to RW, to handle
+ * models using ordinary address_space_rw(), foreign mappings ignore
+ * is_write and are always mapped RW.
+ */
+ vaddr_base = xenforeignmemory_map2(xen_fmem, xen_domid, vaddr,
+ PROT_READ | PROT_WRITE,
+ vaddr ? MAP_FIXED : 0,
+ nb_pfn, pfns, err);
+ }
if (vaddr_base == NULL) {
- perror("xenforeignmemory_map2");
+ perror(grant ? "xengnttab_map_domain_grant_refs"
+ : "xenforeignmemory_map2");
exit(-1);
}
} else {
@@ -260,15 +318,13 @@ static void xen_remap_bucket(MapCache *mc,
bitmap_set(entry->valid_mapping, i, 1);
}
}
-
- g_free(pfns);
- g_free(err);
}
static uint8_t *xen_map_cache_unlocked(MapCache *mc,
hwaddr phys_addr, hwaddr size,
ram_addr_t ram_offset,
- uint8_t lock, bool dma, bool is_write)
+ uint8_t lock, bool dma,
+ bool grant, bool is_write)
{
MapCacheEntry *entry, *pentry = NULL,
*free_entry = NULL, *free_pentry = NULL;
@@ -340,7 +396,7 @@ tryagain:
entry = g_new0(MapCacheEntry, 1);
pentry->next = entry;
xen_remap_bucket(mc, entry, NULL, cache_size, address_index, dummy,
- ram_offset);
+ grant, is_write, ram_offset);
} else if (!entry->lock) {
if (!entry->vaddr_base || entry->paddr_index != address_index ||
entry->size != cache_size ||
@@ -348,7 +404,7 @@ tryagain:
test_bit_size >> XC_PAGE_SHIFT,
entry->valid_mapping)) {
xen_remap_bucket(mc, entry, NULL, cache_size, address_index, dummy,
- ram_offset);
+ grant, is_write, ram_offset);
}
}
@@ -399,12 +455,26 @@ uint8_t *xen_map_cache(MemoryRegion *mr,
uint8_t lock, bool dma,
bool is_write)
{
+ bool grant = xen_mr_is_grants(mr);
+ MapCache *mc = grant ? mapcache_grants : mapcache;
uint8_t *p;
- mapcache_lock(mapcache);
- p = xen_map_cache_unlocked(mapcache, phys_addr, size, ram_addr_offset,
- lock, dma, is_write);
- mapcache_unlock(mapcache);
+ if (grant && !lock) {
+ /*
+ * Grants are only supported via address_space_map(). Anything
+ * else is considered a user/guest error.
+ *
+ * QEMU generally doesn't expect these mappings to ever fail, so
+ * if this happens we report an error message and abort().
+ */
+ error_report("Tried to access a grant reference without mapping it.");
+ abort();
+ }
+
+ mapcache_lock(mc);
+ p = xen_map_cache_unlocked(mc, phys_addr, size, ram_addr_offset,
+ lock, dma, grant, is_write);
+ mapcache_unlock(mc);
return p;
}
@@ -449,7 +519,14 @@ static ram_addr_t xen_ram_addr_from_mapcache_single(MapCache *mc, void *ptr)
ram_addr_t xen_ram_addr_from_mapcache(void *ptr)
{
- return xen_ram_addr_from_mapcache_single(mapcache, ptr);
+ ram_addr_t addr;
+
+ addr = xen_ram_addr_from_mapcache_single(mapcache, ptr);
+ if (addr == RAM_ADDR_INVALID) {
+ addr = xen_ram_addr_from_mapcache_single(mapcache_grants, ptr);
+ }
+
+ return addr;
}
static void xen_invalidate_map_cache_entry_unlocked(MapCache *mc,
@@ -460,6 +537,7 @@ static void xen_invalidate_map_cache_entry_unlocked(MapCache *mc,
hwaddr paddr_index;
hwaddr size;
int found = 0;
+ int rc;
QTAILQ_FOREACH(reventry, &mc->locked_entries, next) {
if (reventry->vaddr_req == buffer) {
@@ -502,7 +580,14 @@ static void xen_invalidate_map_cache_entry_unlocked(MapCache *mc,
}
ram_block_notify_remove(entry->vaddr_base, entry->size, entry->size);
- if (munmap(entry->vaddr_base, entry->size) != 0) {
+ if (entry->flags & XEN_MAPCACHE_ENTRY_GRANT) {
+ rc = xengnttab_unmap(xen_region_gnttabdev, entry->vaddr_base,
+ entry->size >> mc->bucket_shift);
+ } else {
+ rc = munmap(entry->vaddr_base, entry->size);
+ }
+
+ if (rc) {
perror("unmap fails");
exit(-1);
}
@@ -521,14 +606,24 @@ typedef struct XenMapCacheData {
uint8_t *buffer;
} XenMapCacheData;
+static void xen_invalidate_map_cache_entry_single(MapCache *mc, uint8_t *buffer)
+{
+ mapcache_lock(mc);
+ xen_invalidate_map_cache_entry_unlocked(mc, buffer);
+ mapcache_unlock(mc);
+}
+
+static void xen_invalidate_map_cache_entry_all(uint8_t *buffer)
+{
+ xen_invalidate_map_cache_entry_single(mapcache, buffer);
+ xen_invalidate_map_cache_entry_single(mapcache_grants, buffer);
+}
+
static void xen_invalidate_map_cache_entry_bh(void *opaque)
{
XenMapCacheData *data = opaque;
- mapcache_lock(mapcache);
- xen_invalidate_map_cache_entry_unlocked(mapcache, data->buffer);
- mapcache_unlock(mapcache);
-
+ xen_invalidate_map_cache_entry_all(data->buffer);
aio_co_wake(data->co);
}
@@ -543,9 +638,7 @@ void coroutine_mixed_fn xen_invalidate_map_cache_entry(uint8_t *buffer)
xen_invalidate_map_cache_entry_bh, &data);
qemu_coroutine_yield();
} else {
- mapcache_lock(mapcache);
- xen_invalidate_map_cache_entry_unlocked(mapcache, buffer);
- mapcache_unlock(mapcache);
+ xen_invalidate_map_cache_entry_all(buffer);
}
}
@@ -597,6 +690,7 @@ void xen_invalidate_map_cache(void)
bdrv_drain_all();
xen_invalidate_map_cache_single(mapcache);
+ xen_invalidate_map_cache_single(mapcache_grants);
}
static uint8_t *xen_replace_cache_entry_unlocked(MapCache *mc,
@@ -632,13 +726,16 @@ static uint8_t *xen_replace_cache_entry_unlocked(MapCache *mc,
return NULL;
}
+ assert((entry->flags & XEN_MAPCACHE_ENTRY_GRANT) == 0);
+
address_index = new_phys_addr >> mc->bucket_shift;
address_offset = new_phys_addr & (mc->bucket_size - 1);
trace_xen_replace_cache_entry_dummy(old_phys_addr, new_phys_addr);
xen_remap_bucket(mc, entry, entry->vaddr_base,
- cache_size, address_index, false, old_phys_addr);
+ cache_size, address_index, false,
+ false, false, old_phys_addr);
if (!test_bits(address_offset >> XC_PAGE_SHIFT,
test_bit_size >> XC_PAGE_SHIFT,
entry->valid_mapping)) {
diff --git a/include/hw/xen/xen-hvm-common.h b/include/hw/xen/xen-hvm-common.h
index 65a51aac2e..3d796235dc 100644
--- a/include/hw/xen/xen-hvm-common.h
+++ b/include/hw/xen/xen-hvm-common.h
@@ -16,6 +16,7 @@
#include <xen/hvm/ioreq.h>
extern MemoryRegion xen_memory;
+extern MemoryRegion xen_grants;
extern MemoryListener xen_io_listener;
extern DeviceListener xen_device_listener;
@@ -29,6 +30,8 @@ extern DeviceListener xen_device_listener;
do { } while (0)
#endif
+#define XEN_GRANT_ADDR_OFF (1ULL << 63)
+
static inline uint32_t xen_vcpu_eport(shared_iopage_t *shared_page, int i)
{
return shared_page->vcpu_ioreq[i].vp_eport;
diff --git a/include/sysemu/xen.h b/include/sysemu/xen.h
index 3445888e39..d70eacfbe2 100644
--- a/include/sysemu/xen.h
+++ b/include/sysemu/xen.h
@@ -50,4 +50,5 @@ static inline void xen_ram_alloc(ram_addr_t ram_addr, ram_addr_t size,
#endif /* CONFIG_XEN_IS_POSSIBLE */
bool xen_mr_is_memory(MemoryRegion *mr);
+bool xen_mr_is_grants(MemoryRegion *mr);
#endif
--
2.25.1
^ permalink raw reply related [flat|nested] 9+ messages in thread* [PULL 5/5] hw/arm: xen: Enable use of grant mappings
2024-06-12 21:29 [PULL 0/5] virtio-grants-v8-tag Stefano Stabellini
` (3 preceding siblings ...)
2024-06-12 21:29 ` [PULL 4/5] xen: mapcache: Add support for grant mappings Stefano Stabellini
@ 2024-06-12 21:29 ` Stefano Stabellini
2024-06-14 4:04 ` [PULL 0/5] virtio-grants-v8-tag Richard Henderson
2024-06-16 18:04 ` Richard Henderson
6 siblings, 0 replies; 9+ messages in thread
From: Stefano Stabellini @ 2024-06-12 21:29 UTC (permalink / raw)
To: qemu-devel
Cc: stefanha, peter.maydell, sstabellini, Edgar.Iglesias,
Edgar E. Iglesias, Manos Pitsidianakis,
Philippe Mathieu-Daudé
From: "Edgar E. Iglesias" <edgar.iglesias@amd.com>
Signed-off-by: Edgar E. Iglesias <edgar.iglesias@amd.com>
Reviewed-by: Stefano Stabellini <sstabellini@kernel.org>
Reviewed-by: Manos Pitsidianakis <manos.pitsidianakis@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
---
hw/arm/xen_arm.c | 5 +++++
1 file changed, 5 insertions(+)
diff --git a/hw/arm/xen_arm.c b/hw/arm/xen_arm.c
index 15fa7dfa84..6fad829ede 100644
--- a/hw/arm/xen_arm.c
+++ b/hw/arm/xen_arm.c
@@ -125,6 +125,11 @@ static void xen_init_ram(MachineState *machine)
GUEST_RAM1_BASE, ram_size[1]);
memory_region_add_subregion(sysmem, GUEST_RAM1_BASE, &ram_hi);
}
+
+ /* Setup support for grants. */
+ memory_region_init_ram(&xen_grants, NULL, "xen.grants", block_len,
+ &error_fatal);
+ memory_region_add_subregion(sysmem, XEN_GRANT_ADDR_OFF, &xen_grants);
}
void arch_handle_ioreq(XenIOState *state, ioreq_t *req)
--
2.25.1
^ permalink raw reply related [flat|nested] 9+ messages in thread* Re: [PULL 0/5] virtio-grants-v8-tag
2024-06-12 21:29 [PULL 0/5] virtio-grants-v8-tag Stefano Stabellini
` (4 preceding siblings ...)
2024-06-12 21:29 ` [PULL 5/5] hw/arm: xen: Enable use of " Stefano Stabellini
@ 2024-06-14 4:04 ` Richard Henderson
2024-06-14 22:22 ` Stefano Stabellini
2024-06-16 18:04 ` Richard Henderson
6 siblings, 1 reply; 9+ messages in thread
From: Richard Henderson @ 2024-06-14 4:04 UTC (permalink / raw)
To: Stefano Stabellini, qemu-devel, stefanha; +Cc: peter.maydell, Edgar.Iglesias
On 6/12/24 14:29, Stefano Stabellini wrote:
> The following changes since commit 80e8f0602168f451a93e71cbb1d59e93d745e62e:
>
> Merge tag 'virtio-grants-v8-tag' into staging (2024-06-09 11:21:55 -0700)
>
> are available in the Git repository at:
>
> https://gitlab.com/sstabellini/qemu.git
>
> for you to fetch changes up to 6d87a2a311fe4a8363143e6914d000697ea0cd83:
>
> hw/arm: xen: Enable use of grant mappings (2024-06-09 20:16:14 +0200)
gpg: Signature made Wed 12 Jun 2024 02:25:34 PM PDT
gpg: using RSA key D04E33ABA51F67BA07D30AEA894F8F4870E1AE90
gpg: Good signature from "Stefano Stabellini <sstabellini@kernel.org>" [expired]
gpg: aka "Stefano Stabellini <stefano.stabellini@eu.citrix.com>" [expired]
gpg: Note: This key has expired!
Have you posted a refreshed key?
The latest I can find is from 2023-10-19.
r~
^ permalink raw reply [flat|nested] 9+ messages in thread* Re: [PULL 0/5] virtio-grants-v8-tag
2024-06-14 4:04 ` [PULL 0/5] virtio-grants-v8-tag Richard Henderson
@ 2024-06-14 22:22 ` Stefano Stabellini
0 siblings, 0 replies; 9+ messages in thread
From: Stefano Stabellini @ 2024-06-14 22:22 UTC (permalink / raw)
To: Richard Henderson
Cc: Stefano Stabellini, qemu-devel, stefanha, peter.maydell,
Edgar.Iglesias
On Thu, 13 Jun 2024, Richard Henderson wrote:
> On 6/12/24 14:29, Stefano Stabellini wrote:
> > The following changes since commit 80e8f0602168f451a93e71cbb1d59e93d745e62e:
> >
> > Merge tag 'virtio-grants-v8-tag' into staging (2024-06-09 11:21:55 -0700)
> >
> > are available in the Git repository at:
> >
> > https://gitlab.com/sstabellini/qemu.git
> > for you to fetch changes up to 6d87a2a311fe4a8363143e6914d000697ea0cd83:
> >
> > hw/arm: xen: Enable use of grant mappings (2024-06-09 20:16:14 +0200)
>
> gpg: Signature made Wed 12 Jun 2024 02:25:34 PM PDT
> gpg: using RSA key D04E33ABA51F67BA07D30AEA894F8F4870E1AE90
> gpg: Good signature from "Stefano Stabellini <sstabellini@kernel.org>"
> [expired]
> gpg: aka "Stefano Stabellini
> <stefano.stabellini@eu.citrix.com>" [expired]
> gpg: Note: This key has expired!
>
>
> Have you posted a refreshed key?
> The latest I can find is from 2023-10-19.
The key D04E33ABA51F67BA07D30AEA894F8F4870E1AE90 should expire in 2028.
I did another gpg --send-keys to a couple of keyservers and you should
see the new expiration date now (e.g. try keyserver.ubuntu.com and
keys.openpgp.org).
^ permalink raw reply [flat|nested] 9+ messages in thread
* Re: [PULL 0/5] virtio-grants-v8-tag
2024-06-12 21:29 [PULL 0/5] virtio-grants-v8-tag Stefano Stabellini
` (5 preceding siblings ...)
2024-06-14 4:04 ` [PULL 0/5] virtio-grants-v8-tag Richard Henderson
@ 2024-06-16 18:04 ` Richard Henderson
6 siblings, 0 replies; 9+ messages in thread
From: Richard Henderson @ 2024-06-16 18:04 UTC (permalink / raw)
To: Stefano Stabellini, qemu-devel, stefanha; +Cc: peter.maydell, Edgar.Iglesias
On 6/12/24 14:29, Stefano Stabellini wrote:
> The following changes since commit 80e8f0602168f451a93e71cbb1d59e93d745e62e:
>
> Merge tag 'virtio-grants-v8-tag' into staging (2024-06-09 11:21:55 -0700)
>
> are available in the Git repository at:
>
> https://gitlab.com/sstabellini/qemu.git
>
> for you to fetch changes up to 6d87a2a311fe4a8363143e6914d000697ea0cd83:
>
> hw/arm: xen: Enable use of grant mappings (2024-06-09 20:16:14 +0200)
>
> ----------------------------------------------------------------
> Edgar E. Iglesias (5):
> xen: mapcache: Make MCACHE_BUCKET_SHIFT runtime configurable
> xen: mapcache: Unmap first entries in buckets
> xen: mapcache: Pass the ram_addr offset to xen_map_cache()
> xen: mapcache: Add support for grant mappings
> hw/arm: xen: Enable use of grant mappings
Applied, thanks. Please update https://wiki.qemu.org/ChangeLog/9.1 as appropriate.
r~
^ permalink raw reply [flat|nested] 9+ messages in thread