This boolean option 'hmem' allows users to set a memory region from
memory-backend-file as heterogeneous memory. If 'hmem=on', QEMU will
set the flag RAM_HMEM in the RAM block of the corresponding memory
region and set the e820 type to E820_SOFT_RESERVED for this region.
Signed-off-by: Zhigang Luo <zhigang....@amd.com>
---
backends/hostmem-file.c | 23 +++++++++++++++++++++++
hw/i386/e820_memory_layout.h | 1 +
hw/i386/pc.c | 16 ++++++++++++++++
include/exec/cpu-common.h | 1 +
include/exec/memory.h | 3 +++
qapi/qom.json | 4 ++++
system/physmem.c | 7 ++++++-
7 files changed, 54 insertions(+), 1 deletion(-)
diff --git a/backends/hostmem-file.c b/backends/hostmem-file.c
index 7e5072e33e..5ddfdbaf86 100644
--- a/backends/hostmem-file.c
+++ b/backends/hostmem-file.c
@@ -32,6 +32,7 @@ struct HostMemoryBackendFile {
uint64_t offset;
bool discard_data;
bool is_pmem;
+ bool is_hmem;
bool readonly;
OnOffAuto rom;
};
@@ -88,6 +89,7 @@ file_backend_memory_alloc(HostMemoryBackend *backend, Error
**errp)
ram_flags |= backend->reserve ? 0 : RAM_NORESERVE;
ram_flags |= backend->guest_memfd ? RAM_GUEST_MEMFD : 0;
ram_flags |= fb->is_pmem ? RAM_PMEM : 0;
+ ram_flags |= fb->is_hmem ? RAM_HMEM : 0;
ram_flags |= RAM_NAMED_FILE;
return memory_region_init_ram_from_file(&backend->mr, OBJECT(backend),
name,
backend->size, fb->align,
ram_flags,
@@ -256,6 +258,25 @@ static void file_memory_backend_set_rom(Object *obj,
Visitor *v,
visit_type_OnOffAuto(v, name, &fb->rom, errp);
}
+static bool file_memory_backend_get_hmem(Object *o, Error **errp)
+{
+ return MEMORY_BACKEND_FILE(o)->is_hmem;
+}
+
+static void file_memory_backend_set_hmem(Object *o, bool value, Error **errp)
+{
+ HostMemoryBackend *backend = MEMORY_BACKEND(o);
+ HostMemoryBackendFile *fb = MEMORY_BACKEND_FILE(o);
+
+ if (host_memory_backend_mr_inited(backend)) {
+ error_setg(errp, "cannot change property 'hmem' of %s.",
+ object_get_typename(o));
+ return;
+ }
+
+ fb->is_hmem = value;
+}
+
static void file_backend_unparent(Object *obj)
{
HostMemoryBackend *backend = MEMORY_BACKEND(obj);
@@ -295,6 +316,8 @@ file_backend_class_init(ObjectClass *oc, void *data)
object_class_property_add_bool(oc, "pmem",
file_memory_backend_get_pmem, file_memory_backend_set_pmem);
#endif
+ object_class_property_add_bool(oc, "hmem",
+ file_memory_backend_get_hmem, file_memory_backend_set_hmem);
object_class_property_add_bool(oc, "readonly",
file_memory_backend_get_readonly,
file_memory_backend_set_readonly);
diff --git a/hw/i386/e820_memory_layout.h b/hw/i386/e820_memory_layout.h
index b50acfa201..8af6a9cfac 100644
--- a/hw/i386/e820_memory_layout.h
+++ b/hw/i386/e820_memory_layout.h
@@ -15,6 +15,7 @@
#define E820_ACPI 3
#define E820_NVS 4
#define E820_UNUSABLE 5
+#define E820_SOFT_RESERVED 0xEFFFFFFF
struct e820_entry {
uint64_t address;
diff --git a/hw/i386/pc.c b/hw/i386/pc.c
index 317aaca25a..41e9cc276c 100644
--- a/hw/i386/pc.c
+++ b/hw/i386/pc.c
@@ -785,6 +785,21 @@ static hwaddr pc_max_used_gpa(PCMachineState *pcms,
uint64_t pci_hole64_size)
return pc_above_4g_end(pcms) - 1;
}
+static int pc_update_hmem_memory(RAMBlock *rb, void *opaque)
+{
+ X86MachineState *x86ms = opaque;
+ ram_addr_t offset;
+ ram_addr_t length;
+
+ if (qemu_ram_is_hmem(rb)) {
+ offset = qemu_ram_get_offset(rb) + (0x100000000ULL -
x86ms->below_4g_mem_size);
+ length = qemu_ram_get_used_length(rb);
+ e820_add_entry(offset, length, E820_SOFT_RESERVED);
+ }
+
+ return 0;
+}
+
/*
* AMD systems with an IOMMU have an additional hole close to the
* 1Tb, which are special GPAs that cannot be DMA mapped. Depending
@@ -895,6 +910,7 @@ void pc_memory_init(PCMachineState *pcms,
e820_add_entry(x86ms->above_4g_mem_start, x86ms->above_4g_mem_size,
E820_RAM);
}
+ qemu_ram_foreach_block(pc_update_hmem_memory, x86ms);
if (pcms->sgx_epc.size != 0) {
e820_add_entry(pcms->sgx_epc.base, pcms->sgx_epc.size, E820_RESERVED);
diff --git a/include/exec/cpu-common.h b/include/exec/cpu-common.h
index 638dc806a5..1b2dfb31e8 100644
--- a/include/exec/cpu-common.h
+++ b/include/exec/cpu-common.h
@@ -98,6 +98,7 @@ ram_addr_t qemu_ram_get_offset(RAMBlock *rb);
ram_addr_t qemu_ram_get_used_length(RAMBlock *rb);
ram_addr_t qemu_ram_get_max_length(RAMBlock *rb);
bool qemu_ram_is_shared(RAMBlock *rb);
+bool qemu_ram_is_hmem(RAMBlock *rb);
bool qemu_ram_is_noreserve(RAMBlock *rb);
bool qemu_ram_is_uf_zeroable(RAMBlock *rb);
void qemu_ram_set_uf_zeroable(RAMBlock *rb);
diff --git a/include/exec/memory.h b/include/exec/memory.h
index 9458e2801d..18c593a00b 100644
--- a/include/exec/memory.h
+++ b/include/exec/memory.h
@@ -246,6 +246,9 @@ typedef struct IOMMUTLBEvent {
/* RAM can be private that has kvm guest memfd backend */
#define RAM_GUEST_MEMFD (1 << 12)
+/* RAM is a heterogeneous kind memory */
+#define RAM_HMEM (1 << 13)
+
static inline void iommu_notifier_init(IOMMUNotifier *n, IOMMUNotify fn,
IOMMUNotifierFlag flags,
hwaddr start, hwaddr end,
diff --git a/qapi/qom.json b/qapi/qom.json
index 28ce24cd8d..7b8632697f 100644
--- a/qapi/qom.json
+++ b/qapi/qom.json
@@ -669,6 +669,9 @@
# in host persistent memory that can be accessed using the SNIA
# NVM programming model (e.g. Intel NVDIMM).
#
+# @hmem: specifies whether the backing file specified by @mem-path is
+# in host heterogeneous memory.
+#
# @readonly: if true, the backing file is opened read-only; if false,
# it is opened read-write. (default: false)
#
@@ -696,6 +699,7 @@
'*discard-data': 'bool',
'mem-path': 'str',
'*pmem': { 'type': 'bool', 'if': 'CONFIG_LIBPMEM' },
+ '*hmem': 'bool',
'*readonly': 'bool',
'*rom': 'OnOffAuto' } }
diff --git a/system/physmem.c b/system/physmem.c
index dc1db3a384..f703398359 100644
--- a/system/physmem.c
+++ b/system/physmem.c
@@ -1584,6 +1584,11 @@ bool qemu_ram_is_noreserve(RAMBlock *rb)
return rb->flags & RAM_NORESERVE;
}
+bool qemu_ram_is_hmem(RAMBlock *rb)
+{
+ return rb->flags & RAM_HMEM;
+}
+
/* Note: Only set at the start of postcopy */
bool qemu_ram_is_uf_zeroable(RAMBlock *rb)
{
@@ -1951,7 +1956,7 @@ RAMBlock *qemu_ram_alloc_from_fd(ram_addr_t size,
MemoryRegion *mr,
int64_t file_size, file_align;
/* Just support these ram flags by now. */
- assert((ram_flags & ~(RAM_SHARED | RAM_PMEM | RAM_NORESERVE |
+ assert((ram_flags & ~(RAM_SHARED | RAM_PMEM | RAM_HMEM | RAM_NORESERVE |
RAM_PROTECTED | RAM_NAMED_FILE | RAM_READONLY |
RAM_READONLY_FD | RAM_GUEST_MEMFD)) == 0);
--
2.25.1
