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authorJagannathan Raman <jag.raman@oracle.com>2021-01-29 11:46:18 -0500
committerStefan Hajnoczi <stefanha@redhat.com>2021-02-10 09:23:28 +0000
commitc746b74a7d881c7da4afdd7b29353a90c445a8ab (patch)
tree798a89b7087a39b793d5800582d633a6659f6e0b /hw
parent7ee3f82384f07e84f1d2e26a0ab1e5efa7e7f822 (diff)
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multi-process: Synchronize remote memory
Add ProxyMemoryListener object which is used to keep the view of the RAM in sync between QEMU and remote process. A MemoryListener is registered for system-memory AddressSpace. The listener sends SYNC_SYSMEM message to the remote process when memory listener commits the changes to memory, the remote process receives the message and processes it in the handler for SYNC_SYSMEM message. Signed-off-by: Jagannathan Raman <jag.raman@oracle.com> Signed-off-by: John G Johnson <john.g.johnson@oracle.com> Signed-off-by: Elena Ufimtseva <elena.ufimtseva@oracle.com> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> Message-id: 04fe4e6a9ca90d4f11ab6f59be7652f5b086a071.1611938319.git.jag.raman@oracle.com Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Diffstat (limited to 'hw')
-rw-r--r--hw/remote/meson.build1
-rw-r--r--hw/remote/message.c4
-rw-r--r--hw/remote/proxy-memory-listener.c227
-rw-r--r--hw/remote/proxy.c6
4 files changed, 238 insertions, 0 deletions
diff --git a/hw/remote/meson.build b/hw/remote/meson.build
index 569cd20..7f11be4 100644
--- a/hw/remote/meson.build
+++ b/hw/remote/meson.build
@@ -7,5 +7,6 @@ remote_ss.add(when: 'CONFIG_MULTIPROCESS', if_true: files('remote-obj.c'))
remote_ss.add(when: 'CONFIG_MULTIPROCESS', if_true: files('proxy.c'))
specific_ss.add(when: 'CONFIG_MULTIPROCESS', if_true: files('memory.c'))
+specific_ss.add(when: 'CONFIG_MULTIPROCESS', if_true: files('proxy-memory-listener.c'))
softmmu_ss.add_all(when: 'CONFIG_MULTIPROCESS', if_true: remote_ss)
diff --git a/hw/remote/message.c b/hw/remote/message.c
index f2e8445..25341d8 100644
--- a/hw/remote/message.c
+++ b/hw/remote/message.c
@@ -17,6 +17,7 @@
#include "sysemu/runstate.h"
#include "hw/pci/pci.h"
#include "exec/memattrs.h"
+#include "hw/remote/memory.h"
static void process_config_write(QIOChannel *ioc, PCIDevice *dev,
MPQemuMsg *msg, Error **errp);
@@ -61,6 +62,9 @@ void coroutine_fn mpqemu_remote_msg_loop_co(void *data)
case MPQEMU_CMD_BAR_READ:
process_bar_read(com->ioc, &msg, &local_err);
break;
+ case MPQEMU_CMD_SYNC_SYSMEM:
+ remote_sysmem_reconfig(&msg, &local_err);
+ break;
default:
error_setg(&local_err,
"Unknown command (%d) received for device %s"
diff --git a/hw/remote/proxy-memory-listener.c b/hw/remote/proxy-memory-listener.c
new file mode 100644
index 0000000..af1fa6f
--- /dev/null
+++ b/hw/remote/proxy-memory-listener.c
@@ -0,0 +1,227 @@
+/*
+ * Copyright © 2018, 2021 Oracle and/or its affiliates.
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2 or later.
+ * See the COPYING file in the top-level directory.
+ *
+ */
+
+#include "qemu/osdep.h"
+#include "qemu-common.h"
+
+#include "qemu/compiler.h"
+#include "qemu/int128.h"
+#include "qemu/range.h"
+#include "exec/memory.h"
+#include "exec/cpu-common.h"
+#include "cpu.h"
+#include "exec/ram_addr.h"
+#include "exec/address-spaces.h"
+#include "qapi/error.h"
+#include "hw/remote/mpqemu-link.h"
+#include "hw/remote/proxy-memory-listener.h"
+
+/*
+ * TODO: get_fd_from_hostaddr(), proxy_mrs_can_merge() and
+ * proxy_memory_listener_commit() defined below perform tasks similar to the
+ * functions defined in vhost-user.c. These functions are good candidates
+ * for refactoring.
+ *
+ */
+
+static void proxy_memory_listener_reset(MemoryListener *listener)
+{
+ ProxyMemoryListener *proxy_listener = container_of(listener,
+ ProxyMemoryListener,
+ listener);
+ int mrs;
+
+ for (mrs = 0; mrs < proxy_listener->n_mr_sections; mrs++) {
+ memory_region_unref(proxy_listener->mr_sections[mrs].mr);
+ }
+
+ g_free(proxy_listener->mr_sections);
+ proxy_listener->mr_sections = NULL;
+ proxy_listener->n_mr_sections = 0;
+}
+
+static int get_fd_from_hostaddr(uint64_t host, ram_addr_t *offset)
+{
+ MemoryRegion *mr;
+ ram_addr_t off;
+
+ /**
+ * Assumes that the host address is a valid address as it's
+ * coming from the MemoryListener system. In the case host
+ * address is not valid, the following call would return
+ * the default subregion of "system_memory" region, and
+ * not NULL. So it's not possible to check for NULL here.
+ */
+ mr = memory_region_from_host((void *)(uintptr_t)host, &off);
+
+ if (offset) {
+ *offset = off;
+ }
+
+ return memory_region_get_fd(mr);
+}
+
+static bool proxy_mrs_can_merge(uint64_t host, uint64_t prev_host, size_t size)
+{
+ if (((prev_host + size) != host)) {
+ return false;
+ }
+
+ if (get_fd_from_hostaddr(host, NULL) !=
+ get_fd_from_hostaddr(prev_host, NULL)) {
+ return false;
+ }
+
+ return true;
+}
+
+static bool try_merge(ProxyMemoryListener *proxy_listener,
+ MemoryRegionSection *section)
+{
+ uint64_t mrs_size, mrs_gpa, mrs_page;
+ MemoryRegionSection *prev_sec;
+ bool merged = false;
+ uintptr_t mrs_host;
+ RAMBlock *mrs_rb;
+
+ if (!proxy_listener->n_mr_sections) {
+ return false;
+ }
+
+ mrs_rb = section->mr->ram_block;
+ mrs_page = (uint64_t)qemu_ram_pagesize(mrs_rb);
+ mrs_size = int128_get64(section->size);
+ mrs_gpa = section->offset_within_address_space;
+ mrs_host = (uintptr_t)memory_region_get_ram_ptr(section->mr) +
+ section->offset_within_region;
+
+ if (get_fd_from_hostaddr(mrs_host, NULL) < 0) {
+ return true;
+ }
+
+ mrs_host = mrs_host & ~(mrs_page - 1);
+ mrs_gpa = mrs_gpa & ~(mrs_page - 1);
+ mrs_size = ROUND_UP(mrs_size, mrs_page);
+
+ prev_sec = proxy_listener->mr_sections +
+ (proxy_listener->n_mr_sections - 1);
+ uint64_t prev_gpa_start = prev_sec->offset_within_address_space;
+ uint64_t prev_size = int128_get64(prev_sec->size);
+ uint64_t prev_gpa_end = range_get_last(prev_gpa_start, prev_size);
+ uint64_t prev_host_start =
+ (uintptr_t)memory_region_get_ram_ptr(prev_sec->mr) +
+ prev_sec->offset_within_region;
+ uint64_t prev_host_end = range_get_last(prev_host_start, prev_size);
+
+ if (mrs_gpa <= (prev_gpa_end + 1)) {
+ g_assert(mrs_gpa > prev_gpa_start);
+
+ if ((section->mr == prev_sec->mr) &&
+ proxy_mrs_can_merge(mrs_host, prev_host_start,
+ (mrs_gpa - prev_gpa_start))) {
+ uint64_t max_end = MAX(prev_host_end, mrs_host + mrs_size);
+ merged = true;
+ prev_sec->offset_within_address_space =
+ MIN(prev_gpa_start, mrs_gpa);
+ prev_sec->offset_within_region =
+ MIN(prev_host_start, mrs_host) -
+ (uintptr_t)memory_region_get_ram_ptr(prev_sec->mr);
+ prev_sec->size = int128_make64(max_end - MIN(prev_host_start,
+ mrs_host));
+ }
+ }
+
+ return merged;
+}
+
+static void proxy_memory_listener_region_addnop(MemoryListener *listener,
+ MemoryRegionSection *section)
+{
+ ProxyMemoryListener *proxy_listener = container_of(listener,
+ ProxyMemoryListener,
+ listener);
+
+ if (!memory_region_is_ram(section->mr) ||
+ memory_region_is_rom(section->mr)) {
+ return;
+ }
+
+ if (try_merge(proxy_listener, section)) {
+ return;
+ }
+
+ ++proxy_listener->n_mr_sections;
+ proxy_listener->mr_sections = g_renew(MemoryRegionSection,
+ proxy_listener->mr_sections,
+ proxy_listener->n_mr_sections);
+ proxy_listener->mr_sections[proxy_listener->n_mr_sections - 1] = *section;
+ proxy_listener->mr_sections[proxy_listener->n_mr_sections - 1].fv = NULL;
+ memory_region_ref(section->mr);
+}
+
+static void proxy_memory_listener_commit(MemoryListener *listener)
+{
+ ProxyMemoryListener *proxy_listener = container_of(listener,
+ ProxyMemoryListener,
+ listener);
+ MPQemuMsg msg;
+ MemoryRegionSection *section;
+ ram_addr_t offset;
+ uintptr_t host_addr;
+ int region;
+ Error *local_err = NULL;
+
+ memset(&msg, 0, sizeof(MPQemuMsg));
+
+ msg.cmd = MPQEMU_CMD_SYNC_SYSMEM;
+ msg.num_fds = proxy_listener->n_mr_sections;
+ msg.size = sizeof(SyncSysmemMsg);
+ if (msg.num_fds > REMOTE_MAX_FDS) {
+ error_report("Number of fds is more than %d", REMOTE_MAX_FDS);
+ return;
+ }
+
+ for (region = 0; region < proxy_listener->n_mr_sections; region++) {
+ section = &proxy_listener->mr_sections[region];
+ msg.data.sync_sysmem.gpas[region] =
+ section->offset_within_address_space;
+ msg.data.sync_sysmem.sizes[region] = int128_get64(section->size);
+ host_addr = (uintptr_t)memory_region_get_ram_ptr(section->mr) +
+ section->offset_within_region;
+ msg.fds[region] = get_fd_from_hostaddr(host_addr, &offset);
+ msg.data.sync_sysmem.offsets[region] = offset;
+ }
+ if (!mpqemu_msg_send(&msg, proxy_listener->ioc, &local_err)) {
+ error_report_err(local_err);
+ }
+}
+
+void proxy_memory_listener_deconfigure(ProxyMemoryListener *proxy_listener)
+{
+ memory_listener_unregister(&proxy_listener->listener);
+
+ proxy_memory_listener_reset(&proxy_listener->listener);
+}
+
+void proxy_memory_listener_configure(ProxyMemoryListener *proxy_listener,
+ QIOChannel *ioc)
+{
+ proxy_listener->n_mr_sections = 0;
+ proxy_listener->mr_sections = NULL;
+
+ proxy_listener->ioc = ioc;
+
+ proxy_listener->listener.begin = proxy_memory_listener_reset;
+ proxy_listener->listener.commit = proxy_memory_listener_commit;
+ proxy_listener->listener.region_add = proxy_memory_listener_region_addnop;
+ proxy_listener->listener.region_nop = proxy_memory_listener_region_addnop;
+ proxy_listener->listener.priority = 10;
+
+ memory_listener_register(&proxy_listener->listener,
+ &address_space_memory);
+}
diff --git a/hw/remote/proxy.c b/hw/remote/proxy.c
index 22eb422..472b2df 100644
--- a/hw/remote/proxy.c
+++ b/hw/remote/proxy.c
@@ -19,6 +19,8 @@
#include "qemu/sockets.h"
#include "hw/remote/mpqemu-link.h"
#include "qemu/error-report.h"
+#include "hw/remote/proxy-memory-listener.h"
+#include "qom/object.h"
static void pci_proxy_dev_realize(PCIDevice *device, Error **errp)
{
@@ -52,6 +54,8 @@ static void pci_proxy_dev_realize(PCIDevice *device, Error **errp)
qemu_mutex_init(&dev->io_mutex);
qio_channel_set_blocking(dev->ioc, true, NULL);
+
+ proxy_memory_listener_configure(&dev->proxy_listener, dev->ioc);
}
static void pci_proxy_dev_exit(PCIDevice *pdev)
@@ -65,6 +69,8 @@ static void pci_proxy_dev_exit(PCIDevice *pdev)
migrate_del_blocker(dev->migration_blocker);
error_free(dev->migration_blocker);
+
+ proxy_memory_listener_deconfigure(&dev->proxy_listener);
}
static void config_op_send(PCIProxyDev *pdev, uint32_t addr, uint32_t *val,