* [PATCH v5 01/21] pc: Support coldplugging of virtio-pmem-pci devices on all buses
2020-06-26 7:22 [PATCH v5 00/21] virtio-mem: Paravirtualized memory hot(un)plug David Hildenbrand
@ 2020-06-26 7:22 ` David Hildenbrand
2020-06-26 7:22 ` [PATCH v5 02/21] exec: Introduce ram_block_discard_(disable|require)() David Hildenbrand
` (20 subsequent siblings)
21 siblings, 0 replies; 29+ messages in thread
From: David Hildenbrand @ 2020-06-26 7:22 UTC (permalink / raw)
To: qemu-devel
Cc: kvm, qemu-s390x, Richard Henderson, Paolo Bonzini,
Dr . David Alan Gilbert, Eduardo Habkost, Michael S . Tsirkin,
David Hildenbrand, Vivek Goyal, Pankaj Gupta, Igor Mammedov,
Marcel Apfelbaum
E.g., with "pc-q35-4.2", trying to coldplug a virtio-pmem-pci devices
results in
"virtio-pmem-pci not supported on this bus"
Reasons is, that the bus does not support hotplug and, therefore, does
not have a hotplug handler. Let's allow coldplugging virtio-pmem devices
on such buses. The hotplug order is only relevant for virtio-pmem-pci
when the guest is already alive and the device is visible before
memory_device_plug() wired up the memory device bits.
Hotplug attempts will still fail with:
"Error: Bus 'pcie.0' does not support hotplugging"
Hotunplug attempts will still fail with:
"Error: Bus 'pcie.0' does not support hotplugging"
Reported-by: Vivek Goyal <vgoyal@redhat.com>
Reviewed-by: Pankaj Gupta <pankaj.gupta.linux@gmail.com>
Cc: Pankaj Gupta <pankaj.gupta.linux@gmail.com>
Cc: Igor Mammedov <imammedo@redhat.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Richard Henderson <rth@twiddle.net>
Cc: Eduardo Habkost <ehabkost@redhat.com>
Cc: "Michael S. Tsirkin" <mst@redhat.com>
Cc: Marcel Apfelbaum <marcel.apfelbaum@gmail.com>
Signed-off-by: David Hildenbrand <david@redhat.com>
---
hw/i386/pc.c | 18 ++++++++++--------
1 file changed, 10 insertions(+), 8 deletions(-)
diff --git a/hw/i386/pc.c b/hw/i386/pc.c
index 803bd52ca4..2dfd69b973 100644
--- a/hw/i386/pc.c
+++ b/hw/i386/pc.c
@@ -1643,13 +1643,13 @@ static void pc_virtio_pmem_pci_pre_plug(HotplugHandler *hotplug_dev,
HotplugHandler *hotplug_dev2 = qdev_get_bus_hotplug_handler(dev);
Error *local_err = NULL;
- if (!hotplug_dev2) {
+ if (!hotplug_dev2 && dev->hotplugged) {
/*
* Without a bus hotplug handler, we cannot control the plug/unplug
- * order. This should never be the case on x86, however better add
- * a safety net.
+ * order. We should never reach this point when hotplugging on x86,
+ * however, better add a safety net.
*/
- error_setg(errp, "virtio-pmem-pci not supported on this bus.");
+ error_setg(errp, "virtio-pmem-pci hotplug not supported on this bus.");
return;
}
/*
@@ -1658,7 +1658,7 @@ static void pc_virtio_pmem_pci_pre_plug(HotplugHandler *hotplug_dev,
*/
memory_device_pre_plug(MEMORY_DEVICE(dev), MACHINE(hotplug_dev), NULL,
&local_err);
- if (!local_err) {
+ if (!local_err && hotplug_dev2) {
hotplug_handler_pre_plug(hotplug_dev2, dev, &local_err);
}
error_propagate(errp, local_err);
@@ -1676,9 +1676,11 @@ static void pc_virtio_pmem_pci_plug(HotplugHandler *hotplug_dev,
* device bits.
*/
memory_device_plug(MEMORY_DEVICE(dev), MACHINE(hotplug_dev));
- hotplug_handler_plug(hotplug_dev2, dev, &local_err);
- if (local_err) {
- memory_device_unplug(MEMORY_DEVICE(dev), MACHINE(hotplug_dev));
+ if (hotplug_dev2) {
+ hotplug_handler_plug(hotplug_dev2, dev, &local_err);
+ if (local_err) {
+ memory_device_unplug(MEMORY_DEVICE(dev), MACHINE(hotplug_dev));
+ }
}
error_propagate(errp, local_err);
}
--
2.26.2
^ permalink raw reply related [flat|nested] 29+ messages in thread* [PATCH v5 02/21] exec: Introduce ram_block_discard_(disable|require)()
2020-06-26 7:22 [PATCH v5 00/21] virtio-mem: Paravirtualized memory hot(un)plug David Hildenbrand
2020-06-26 7:22 ` [PATCH v5 01/21] pc: Support coldplugging of virtio-pmem-pci devices on all buses David Hildenbrand
@ 2020-06-26 7:22 ` David Hildenbrand
2020-06-26 7:22 ` [PATCH v5 03/21] vfio: Convert to ram_block_discard_disable() David Hildenbrand
` (19 subsequent siblings)
21 siblings, 0 replies; 29+ messages in thread
From: David Hildenbrand @ 2020-06-26 7:22 UTC (permalink / raw)
To: qemu-devel
Cc: kvm, qemu-s390x, Richard Henderson, Paolo Bonzini,
Dr . David Alan Gilbert, Eduardo Habkost, Michael S . Tsirkin,
David Hildenbrand
We want to replace qemu_balloon_inhibit() by something more generic.
Especially, we want to make sure that technologies that really rely on
RAM block discards to work reliably to run mutual exclusive with
technologies that effectively break it.
E.g., vfio will usually pin all guest memory, turning the virtio-balloon
basically useless and make the VM consume more memory than reported via
the balloon. While the balloon is special already (=> no guarantees, same
behavior possible afer reboots and with huge pages), this will be
different, especially, with virtio-mem.
Let's implement a way such that we can make both types of technology run
mutually exclusive. We'll convert existing balloon inhibitors in successive
patches and add some new ones. Add the check to
qemu_balloon_is_inhibited() for now. We might want to make
virtio-balloon an acutal inhibitor in the future - however, that
requires more thought to not break existing setups.
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Cc: "Michael S. Tsirkin" <mst@redhat.com>
Cc: Richard Henderson <rth@twiddle.net>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: David Hildenbrand <david@redhat.com>
---
balloon.c | 3 ++-
exec.c | 52 +++++++++++++++++++++++++++++++++++++++++++
include/exec/memory.h | 41 ++++++++++++++++++++++++++++++++++
3 files changed, 95 insertions(+), 1 deletion(-)
diff --git a/balloon.c b/balloon.c
index f104b42961..5fff79523a 100644
--- a/balloon.c
+++ b/balloon.c
@@ -40,7 +40,8 @@ static int balloon_inhibit_count;
bool qemu_balloon_is_inhibited(void)
{
- return atomic_read(&balloon_inhibit_count) > 0;
+ return atomic_read(&balloon_inhibit_count) > 0 ||
+ ram_block_discard_is_disabled();
}
void qemu_balloon_inhibit(bool state)
diff --git a/exec.c b/exec.c
index d6712fba7e..b15187d9ab 100644
--- a/exec.c
+++ b/exec.c
@@ -4063,4 +4063,56 @@ void mtree_print_dispatch(AddressSpaceDispatch *d, MemoryRegion *root)
}
}
+/*
+ * If positive, discarding RAM is disabled. If negative, discarding RAM is
+ * required to work and cannot be disabled.
+ */
+static int ram_block_discard_disabled;
+
+int ram_block_discard_disable(bool state)
+{
+ int old;
+
+ if (!state) {
+ atomic_dec(&ram_block_discard_disabled);
+ return 0;
+ }
+
+ do {
+ old = atomic_read(&ram_block_discard_disabled);
+ if (old < 0) {
+ return -EBUSY;
+ }
+ } while (atomic_cmpxchg(&ram_block_discard_disabled, old, old + 1) != old);
+ return 0;
+}
+
+int ram_block_discard_require(bool state)
+{
+ int old;
+
+ if (!state) {
+ atomic_inc(&ram_block_discard_disabled);
+ return 0;
+ }
+
+ do {
+ old = atomic_read(&ram_block_discard_disabled);
+ if (old > 0) {
+ return -EBUSY;
+ }
+ } while (atomic_cmpxchg(&ram_block_discard_disabled, old, old - 1) != old);
+ return 0;
+}
+
+bool ram_block_discard_is_disabled(void)
+{
+ return atomic_read(&ram_block_discard_disabled) > 0;
+}
+
+bool ram_block_discard_is_required(void)
+{
+ return atomic_read(&ram_block_discard_disabled) < 0;
+}
+
#endif
diff --git a/include/exec/memory.h b/include/exec/memory.h
index 7207025bd4..38ec38b9a8 100644
--- a/include/exec/memory.h
+++ b/include/exec/memory.h
@@ -2472,6 +2472,47 @@ static inline MemOp devend_memop(enum device_endian end)
}
#endif
+/*
+ * Inhibit technologies that require discarding of pages in RAM blocks, e.g.,
+ * to manage the actual amount of memory consumed by the VM (then, the memory
+ * provided by RAM blocks might be bigger than the desired memory consumption).
+ * This *must* be set if:
+ * - Discarding parts of a RAM blocks does not result in the change being
+ * reflected in the VM and the pages getting freed.
+ * - All memory in RAM blocks is pinned or duplicated, invaldiating any previous
+ * discards blindly.
+ * - Discarding parts of a RAM blocks will result in integrity issues (e.g.,
+ * encrypted VMs).
+ * Technologies that only temporarily pin the current working set of a
+ * driver are fine, because we don't expect such pages to be discarded
+ * (esp. based on guest action like balloon inflation).
+ *
+ * This is *not* to be used to protect from concurrent discards (esp.,
+ * postcopy).
+ *
+ * Returns 0 if successful. Returns -EBUSY if a technology that relies on
+ * discards to work reliably is active.
+ */
+int ram_block_discard_disable(bool state);
+
+/*
+ * Inhibit technologies that disable discarding of pages in RAM blocks.
+ *
+ * Returns 0 if successful. Returns -EBUSY if discards are already set to
+ * broken.
+ */
+int ram_block_discard_require(bool state);
+
+/*
+ * Test if discarding of memory in ram blocks is disabled.
+ */
+bool ram_block_discard_is_disabled(void);
+
+/*
+ * Test if discarding of memory in ram blocks is required to work reliably.
+ */
+bool ram_block_discard_is_required(void);
+
#endif
#endif
--
2.26.2
^ permalink raw reply related [flat|nested] 29+ messages in thread* [PATCH v5 03/21] vfio: Convert to ram_block_discard_disable()
2020-06-26 7:22 [PATCH v5 00/21] virtio-mem: Paravirtualized memory hot(un)plug David Hildenbrand
2020-06-26 7:22 ` [PATCH v5 01/21] pc: Support coldplugging of virtio-pmem-pci devices on all buses David Hildenbrand
2020-06-26 7:22 ` [PATCH v5 02/21] exec: Introduce ram_block_discard_(disable|require)() David Hildenbrand
@ 2020-06-26 7:22 ` David Hildenbrand
2020-06-26 7:22 ` [PATCH v5 04/21] accel/kvm: " David Hildenbrand
` (18 subsequent siblings)
21 siblings, 0 replies; 29+ messages in thread
From: David Hildenbrand @ 2020-06-26 7:22 UTC (permalink / raw)
To: qemu-devel
Cc: kvm, qemu-s390x, Richard Henderson, Paolo Bonzini,
Dr . David Alan Gilbert, Eduardo Habkost, Michael S . Tsirkin,
David Hildenbrand, Tony Krowiak, Cornelia Huck, Alex Williamson,
Christian Borntraeger, Halil Pasic, Pierre Morel, Eric Farman
VFIO is (except devices without a physical IOMMU or some mediated devices)
incompatible with discarding of RAM. The kernel will pin basically all VM
memory. Let's convert to ram_block_discard_disable(), which can now
fail, in contrast to qemu_balloon_inhibit().
Leave "x-balloon-allowed" named as it is for now.
Reviewed-by: Tony Krowiak <akrowiak@linux.ibm.com>
Acked-by: Cornelia Huck <cohuck@redhat.com>
Cc: Cornelia Huck <cohuck@redhat.com>
Cc: Alex Williamson <alex.williamson@redhat.com>
Cc: Christian Borntraeger <borntraeger@de.ibm.com>
Cc: Tony Krowiak <akrowiak@linux.ibm.com>
Cc: Halil Pasic <pasic@linux.ibm.com>
Cc: Pierre Morel <pmorel@linux.ibm.com>
Cc: Eric Farman <farman@linux.ibm.com>
Signed-off-by: David Hildenbrand <david@redhat.com>
---
hw/vfio/ap.c | 8 +++---
hw/vfio/ccw.c | 11 ++++----
hw/vfio/common.c | 53 +++++++++++++++++++----------------
hw/vfio/pci.c | 6 ++--
include/hw/vfio/vfio-common.h | 4 +--
5 files changed, 44 insertions(+), 38 deletions(-)
diff --git a/hw/vfio/ap.c b/hw/vfio/ap.c
index 95564c17ed..b9330a8e6f 100644
--- a/hw/vfio/ap.c
+++ b/hw/vfio/ap.c
@@ -105,12 +105,12 @@ static void vfio_ap_realize(DeviceState *dev, Error **errp)
vapdev->vdev.dev = dev;
/*
- * vfio-ap devices operate in a way compatible with
- * memory ballooning, as no pages are pinned in the host.
+ * vfio-ap devices operate in a way compatible with discarding of
+ * memory in RAM blocks, as no pages are pinned in the host.
* This needs to be set before vfio_get_device() for vfio common to
- * handle the balloon inhibitor.
+ * handle ram_block_discard_disable().
*/
- vapdev->vdev.balloon_allowed = true;
+ vapdev->vdev.ram_block_discard_allowed = true;
ret = vfio_get_device(vfio_group, mdevid, &vapdev->vdev, errp);
if (ret) {
diff --git a/hw/vfio/ccw.c b/hw/vfio/ccw.c
index 06e69d7066..ff7f369779 100644
--- a/hw/vfio/ccw.c
+++ b/hw/vfio/ccw.c
@@ -574,12 +574,13 @@ static void vfio_ccw_get_device(VFIOGroup *group, VFIOCCWDevice *vcdev,
/*
* All vfio-ccw devices are believed to operate in a way compatible with
- * memory ballooning, ie. pages pinned in the host are in the current
- * working set of the guest driver and therefore never overlap with pages
- * available to the guest balloon driver. This needs to be set before
- * vfio_get_device() for vfio common to handle the balloon inhibitor.
+ * discarding of memory in RAM blocks, ie. pages pinned in the host are
+ * in the current working set of the guest driver and therefore never
+ * overlap e.g., with pages available to the guest balloon driver. This
+ * needs to be set before vfio_get_device() for vfio common to handle
+ * ram_block_discard_disable().
*/
- vcdev->vdev.balloon_allowed = true;
+ vcdev->vdev.ram_block_discard_allowed = true;
if (vfio_get_device(group, vcdev->cdev.mdevid, &vcdev->vdev, errp)) {
goto out_err;
diff --git a/hw/vfio/common.c b/hw/vfio/common.c
index 0b3593b3c0..33357140b8 100644
--- a/hw/vfio/common.c
+++ b/hw/vfio/common.c
@@ -33,7 +33,6 @@
#include "qemu/error-report.h"
#include "qemu/main-loop.h"
#include "qemu/range.h"
-#include "sysemu/balloon.h"
#include "sysemu/kvm.h"
#include "sysemu/reset.h"
#include "trace.h"
@@ -1215,31 +1214,36 @@ static int vfio_connect_container(VFIOGroup *group, AddressSpace *as,
space = vfio_get_address_space(as);
/*
- * VFIO is currently incompatible with memory ballooning insofar as the
+ * VFIO is currently incompatible with discarding of RAM insofar as the
* madvise to purge (zap) the page from QEMU's address space does not
* interact with the memory API and therefore leaves stale virtual to
* physical mappings in the IOMMU if the page was previously pinned. We
- * therefore add a balloon inhibit for each group added to a container,
+ * therefore set discarding broken for each group added to a container,
* whether the container is used individually or shared. This provides
* us with options to allow devices within a group to opt-in and allow
- * ballooning, so long as it is done consistently for a group (for instance
+ * discarding, so long as it is done consistently for a group (for instance
* if the device is an mdev device where it is known that the host vendor
* driver will never pin pages outside of the working set of the guest
- * driver, which would thus not be ballooning candidates).
+ * driver, which would thus not be discarding candidates).
*
* The first opportunity to induce pinning occurs here where we attempt to
* attach the group to existing containers within the AddressSpace. If any
- * pages are already zapped from the virtual address space, such as from a
- * previous ballooning opt-in, new pinning will cause valid mappings to be
+ * pages are already zapped from the virtual address space, such as from
+ * previous discards, new pinning will cause valid mappings to be
* re-established. Likewise, when the overall MemoryListener for a new
* container is registered, a replay of mappings within the AddressSpace
* will occur, re-establishing any previously zapped pages as well.
*
- * NB. Balloon inhibiting does not currently block operation of the
- * balloon driver or revoke previously pinned pages, it only prevents
- * calling madvise to modify the virtual mapping of ballooned pages.
+ * Especially virtio-balloon is currently only prevented from discarding
+ * new memory, it will not yet set ram_block_discard_set_required() and
+ * therefore, neither stops us here or deals with the sudden memory
+ * consumption of inflated memory.
*/
- qemu_balloon_inhibit(true);
+ ret = ram_block_discard_disable(true);
+ if (ret) {
+ error_setg_errno(errp, -ret, "Cannot set discarding of RAM broken");
+ return ret;
+ }
QLIST_FOREACH(container, &space->containers, next) {
if (!ioctl(group->fd, VFIO_GROUP_SET_CONTAINER, &container->fd)) {
@@ -1405,7 +1409,7 @@ close_fd_exit:
close(fd);
put_space_exit:
- qemu_balloon_inhibit(false);
+ ram_block_discard_disable(false);
vfio_put_address_space(space);
return ret;
@@ -1526,8 +1530,8 @@ void vfio_put_group(VFIOGroup *group)
return;
}
- if (!group->balloon_allowed) {
- qemu_balloon_inhibit(false);
+ if (!group->ram_block_discard_allowed) {
+ ram_block_discard_disable(false);
}
vfio_kvm_device_del_group(group);
vfio_disconnect_container(group);
@@ -1565,22 +1569,23 @@ int vfio_get_device(VFIOGroup *group, const char *name,
}
/*
- * Clear the balloon inhibitor for this group if the driver knows the
- * device operates compatibly with ballooning. Setting must be consistent
- * per group, but since compatibility is really only possible with mdev
- * currently, we expect singleton groups.
+ * Set discarding of RAM as not broken for this group if the driver knows
+ * the device operates compatibly with discarding. Setting must be
+ * consistent per group, but since compatibility is really only possible
+ * with mdev currently, we expect singleton groups.
*/
- if (vbasedev->balloon_allowed != group->balloon_allowed) {
+ if (vbasedev->ram_block_discard_allowed !=
+ group->ram_block_discard_allowed) {
if (!QLIST_EMPTY(&group->device_list)) {
- error_setg(errp,
- "Inconsistent device balloon setting within group");
+ error_setg(errp, "Inconsistent setting of support for discarding "
+ "RAM (e.g., balloon) within group");
close(fd);
return -1;
}
- if (!group->balloon_allowed) {
- group->balloon_allowed = true;
- qemu_balloon_inhibit(false);
+ if (!group->ram_block_discard_allowed) {
+ group->ram_block_discard_allowed = true;
+ ram_block_discard_disable(false);
}
}
diff --git a/hw/vfio/pci.c b/hw/vfio/pci.c
index 6838bcc4b3..d020ea9f82 100644
--- a/hw/vfio/pci.c
+++ b/hw/vfio/pci.c
@@ -2789,7 +2789,7 @@ static void vfio_realize(PCIDevice *pdev, Error **errp)
}
/*
- * Mediated devices *might* operate compatibly with memory ballooning, but
+ * Mediated devices *might* operate compatibly with discarding of RAM, but
* we cannot know for certain, it depends on whether the mdev vendor driver
* stays in sync with the active working set of the guest driver. Prevent
* the x-balloon-allowed option unless this is minimally an mdev device.
@@ -2802,7 +2802,7 @@ static void vfio_realize(PCIDevice *pdev, Error **errp)
trace_vfio_mdev(vdev->vbasedev.name, is_mdev);
- if (vdev->vbasedev.balloon_allowed && !is_mdev) {
+ if (vdev->vbasedev.ram_block_discard_allowed && !is_mdev) {
error_setg(errp, "x-balloon-allowed only potentially compatible "
"with mdev devices");
vfio_put_group(group);
@@ -3156,7 +3156,7 @@ static Property vfio_pci_dev_properties[] = {
VFIO_FEATURE_ENABLE_IGD_OPREGION_BIT, false),
DEFINE_PROP_BOOL("x-no-mmap", VFIOPCIDevice, vbasedev.no_mmap, false),
DEFINE_PROP_BOOL("x-balloon-allowed", VFIOPCIDevice,
- vbasedev.balloon_allowed, false),
+ vbasedev.ram_block_discard_allowed, false),
DEFINE_PROP_BOOL("x-no-kvm-intx", VFIOPCIDevice, no_kvm_intx, false),
DEFINE_PROP_BOOL("x-no-kvm-msi", VFIOPCIDevice, no_kvm_msi, false),
DEFINE_PROP_BOOL("x-no-kvm-msix", VFIOPCIDevice, no_kvm_msix, false),
diff --git a/include/hw/vfio/vfio-common.h b/include/hw/vfio/vfio-common.h
index fd564209ac..c78f3ff559 100644
--- a/include/hw/vfio/vfio-common.h
+++ b/include/hw/vfio/vfio-common.h
@@ -108,7 +108,7 @@ typedef struct VFIODevice {
bool reset_works;
bool needs_reset;
bool no_mmap;
- bool balloon_allowed;
+ bool ram_block_discard_allowed;
VFIODeviceOps *ops;
unsigned int num_irqs;
unsigned int num_regions;
@@ -128,7 +128,7 @@ typedef struct VFIOGroup {
QLIST_HEAD(, VFIODevice) device_list;
QLIST_ENTRY(VFIOGroup) next;
QLIST_ENTRY(VFIOGroup) container_next;
- bool balloon_allowed;
+ bool ram_block_discard_allowed;
} VFIOGroup;
typedef struct VFIODMABuf {
--
2.26.2
^ permalink raw reply related [flat|nested] 29+ messages in thread* [PATCH v5 04/21] accel/kvm: Convert to ram_block_discard_disable()
2020-06-26 7:22 [PATCH v5 00/21] virtio-mem: Paravirtualized memory hot(un)plug David Hildenbrand
` (2 preceding siblings ...)
2020-06-26 7:22 ` [PATCH v5 03/21] vfio: Convert to ram_block_discard_disable() David Hildenbrand
@ 2020-06-26 7:22 ` David Hildenbrand
2020-06-26 7:22 ` [PATCH v5 05/21] s390x/pv: " David Hildenbrand
` (17 subsequent siblings)
21 siblings, 0 replies; 29+ messages in thread
From: David Hildenbrand @ 2020-06-26 7:22 UTC (permalink / raw)
To: qemu-devel
Cc: kvm, qemu-s390x, Richard Henderson, Paolo Bonzini,
Dr . David Alan Gilbert, Eduardo Habkost, Michael S . Tsirkin,
David Hildenbrand
Discarding memory does not work as expected. At the time this is called,
we cannot have anyone active that relies on discards to work properly.
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: David Hildenbrand <david@redhat.com>
---
accel/kvm/kvm-all.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/accel/kvm/kvm-all.c b/accel/kvm/kvm-all.c
index f24d7da783..4751ce67a9 100644
--- a/accel/kvm/kvm-all.c
+++ b/accel/kvm/kvm-all.c
@@ -40,7 +40,6 @@
#include "trace.h"
#include "hw/irq.h"
#include "sysemu/sev.h"
-#include "sysemu/balloon.h"
#include "qapi/visitor.h"
#include "qapi/qapi-types-common.h"
#include "qapi/qapi-visit-common.h"
@@ -2222,7 +2221,8 @@ static int kvm_init(MachineState *ms)
s->sync_mmu = !!kvm_vm_check_extension(kvm_state, KVM_CAP_SYNC_MMU);
if (!s->sync_mmu) {
- qemu_balloon_inhibit(true);
+ ret = ram_block_discard_disable(true);
+ assert(!ret);
}
return 0;
--
2.26.2
^ permalink raw reply related [flat|nested] 29+ messages in thread* [PATCH v5 05/21] s390x/pv: Convert to ram_block_discard_disable()
2020-06-26 7:22 [PATCH v5 00/21] virtio-mem: Paravirtualized memory hot(un)plug David Hildenbrand
` (3 preceding siblings ...)
2020-06-26 7:22 ` [PATCH v5 04/21] accel/kvm: " David Hildenbrand
@ 2020-06-26 7:22 ` David Hildenbrand
2020-06-26 7:22 ` [PATCH v5 06/21] virtio-balloon: Rip out qemu_balloon_inhibit() David Hildenbrand
` (16 subsequent siblings)
21 siblings, 0 replies; 29+ messages in thread
From: David Hildenbrand @ 2020-06-26 7:22 UTC (permalink / raw)
To: qemu-devel
Cc: kvm, qemu-s390x, Richard Henderson, Paolo Bonzini,
Dr . David Alan Gilbert, Eduardo Habkost, Michael S . Tsirkin,
David Hildenbrand, Cornelia Huck, Halil Pasic,
Christian Borntraeger, Janosch Frank
Discarding RAM does not work as expected with protected VMs. Let's
switch to ram_block_discard_disable() for now, as we want to get rid
of qemu_balloon_inhibit(). Note that it will currently never fail, but
might fail in the future with new technologies (e.g., virtio-mem).
Acked-by: Cornelia Huck <cohuck@redhat.com>
Cc: Richard Henderson <rth@twiddle.net>
Cc: Cornelia Huck <cohuck@redhat.com>
Cc: Halil Pasic <pasic@linux.ibm.com>
Cc: Christian Borntraeger <borntraeger@de.ibm.com>
Cc: Janosch Frank <frankja@linux.ibm.com>
Signed-off-by: David Hildenbrand <david@redhat.com>
---
hw/s390x/s390-virtio-ccw.c | 22 +++++++++++++---------
1 file changed, 13 insertions(+), 9 deletions(-)
diff --git a/hw/s390x/s390-virtio-ccw.c b/hw/s390x/s390-virtio-ccw.c
index b111406d56..023fd25f2b 100644
--- a/hw/s390x/s390-virtio-ccw.c
+++ b/hw/s390x/s390-virtio-ccw.c
@@ -43,7 +43,6 @@
#include "hw/qdev-properties.h"
#include "hw/s390x/tod.h"
#include "sysemu/sysemu.h"
-#include "sysemu/balloon.h"
#include "hw/s390x/pv.h"
#include "migration/blocker.h"
@@ -329,7 +328,7 @@ static void s390_machine_unprotect(S390CcwMachineState *ms)
ms->pv = false;
migrate_del_blocker(pv_mig_blocker);
error_free_or_abort(&pv_mig_blocker);
- qemu_balloon_inhibit(false);
+ ram_block_discard_disable(false);
}
static int s390_machine_protect(S390CcwMachineState *ms)
@@ -338,17 +337,22 @@ static int s390_machine_protect(S390CcwMachineState *ms)
int rc;
/*
- * Ballooning on protected VMs needs support in the guest for
- * sharing and unsharing balloon pages. Block ballooning for
- * now, until we have a solution to make at least Linux guests
- * either support it or fail gracefully.
+ * Discarding of memory in RAM blocks does not work as expected with
+ * protected VMs. Sharing and unsharing pages would be required. Disable
+ * it for now, until until we have a solution to make at least Linux
+ * guests either support it (e.g., virtio-balloon) or fail gracefully.
*/
- qemu_balloon_inhibit(true);
+ rc = ram_block_discard_disable(true);
+ if (rc) {
+ error_report("protected VMs: cannot disable RAM discard");
+ return rc;
+ }
+
error_setg(&pv_mig_blocker,
"protected VMs are currently not migrateable.");
rc = migrate_add_blocker(pv_mig_blocker, &local_err);
if (rc) {
- qemu_balloon_inhibit(false);
+ ram_block_discard_disable(false);
error_report_err(local_err);
error_free_or_abort(&pv_mig_blocker);
return rc;
@@ -357,7 +361,7 @@ static int s390_machine_protect(S390CcwMachineState *ms)
/* Create SE VM */
rc = s390_pv_vm_enable();
if (rc) {
- qemu_balloon_inhibit(false);
+ ram_block_discard_disable(false);
migrate_del_blocker(pv_mig_blocker);
error_free_or_abort(&pv_mig_blocker);
return rc;
--
2.26.2
^ permalink raw reply related [flat|nested] 29+ messages in thread* [PATCH v5 06/21] virtio-balloon: Rip out qemu_balloon_inhibit()
2020-06-26 7:22 [PATCH v5 00/21] virtio-mem: Paravirtualized memory hot(un)plug David Hildenbrand
` (4 preceding siblings ...)
2020-06-26 7:22 ` [PATCH v5 05/21] s390x/pv: " David Hildenbrand
@ 2020-06-26 7:22 ` David Hildenbrand
2020-06-26 7:22 ` [PATCH v5 07/21] target/i386: sev: Use ram_block_discard_disable() David Hildenbrand
` (15 subsequent siblings)
21 siblings, 0 replies; 29+ messages in thread
From: David Hildenbrand @ 2020-06-26 7:22 UTC (permalink / raw)
To: qemu-devel
Cc: kvm, qemu-s390x, Richard Henderson, Paolo Bonzini,
Dr . David Alan Gilbert, Eduardo Habkost, Michael S . Tsirkin,
David Hildenbrand, Juan Quintela
The only remaining special case is postcopy. It cannot handle
concurrent discards yet, which would result in requesting already sent
pages from the source. Special-case it in virtio-balloon instead.
Introduce migration_in_incoming_postcopy(), to find out if incoming
postcopy is active.
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Cc: "Michael S. Tsirkin" <mst@redhat.com>
Cc: Juan Quintela <quintela@redhat.com>
Cc: "Dr. David Alan Gilbert" <dgilbert@redhat.com>
Signed-off-by: David Hildenbrand <david@redhat.com>
---
balloon.c | 18 ------------------
hw/virtio/virtio-balloon.c | 10 ++++++++--
include/migration/misc.h | 2 ++
include/sysemu/balloon.h | 2 --
migration/migration.c | 7 +++++++
migration/postcopy-ram.c | 23 -----------------------
6 files changed, 17 insertions(+), 45 deletions(-)
diff --git a/balloon.c b/balloon.c
index 5fff79523a..354408c6ea 100644
--- a/balloon.c
+++ b/balloon.c
@@ -36,24 +36,6 @@
static QEMUBalloonEvent *balloon_event_fn;
static QEMUBalloonStatus *balloon_stat_fn;
static void *balloon_opaque;
-static int balloon_inhibit_count;
-
-bool qemu_balloon_is_inhibited(void)
-{
- return atomic_read(&balloon_inhibit_count) > 0 ||
- ram_block_discard_is_disabled();
-}
-
-void qemu_balloon_inhibit(bool state)
-{
- if (state) {
- atomic_inc(&balloon_inhibit_count);
- } else {
- atomic_dec(&balloon_inhibit_count);
- }
-
- assert(atomic_read(&balloon_inhibit_count) >= 0);
-}
static bool have_balloon(Error **errp)
{
diff --git a/hw/virtio/virtio-balloon.c b/hw/virtio/virtio-balloon.c
index 10507b2a43..5faa9de558 100644
--- a/hw/virtio/virtio-balloon.c
+++ b/hw/virtio/virtio-balloon.c
@@ -63,6 +63,12 @@ static bool virtio_balloon_pbp_matches(PartiallyBalloonedPage *pbp,
return pbp->base_gpa == base_gpa;
}
+static bool virtio_balloon_inhibited(void)
+{
+ /* Postcopy cannot deal with concurrent discards, so it's special. */
+ return ram_block_discard_is_disabled() || migration_in_incoming_postcopy();
+}
+
static void balloon_inflate_page(VirtIOBalloon *balloon,
MemoryRegion *mr, hwaddr mr_offset,
PartiallyBalloonedPage *pbp)
@@ -336,7 +342,7 @@ static void virtio_balloon_handle_report(VirtIODevice *vdev, VirtQueue *vq)
* accessible by another device or process, or if the guest is
* expecting it to retain a non-zero value.
*/
- if (qemu_balloon_is_inhibited() || dev->poison_val) {
+ if (virtio_balloon_inhibited() || dev->poison_val) {
goto skip_element;
}
@@ -421,7 +427,7 @@ static void virtio_balloon_handle_output(VirtIODevice *vdev, VirtQueue *vq)
trace_virtio_balloon_handle_output(memory_region_name(section.mr),
pa);
- if (!qemu_balloon_is_inhibited()) {
+ if (!virtio_balloon_inhibited()) {
if (vq == s->ivq) {
balloon_inflate_page(s, section.mr,
section.offset_within_region, &pbp);
diff --git a/include/migration/misc.h b/include/migration/misc.h
index d2762257aa..34e7d75713 100644
--- a/include/migration/misc.h
+++ b/include/migration/misc.h
@@ -69,6 +69,8 @@ bool migration_has_failed(MigrationState *);
/* ...and after the device transmission */
bool migration_in_postcopy_after_devices(MigrationState *);
void migration_global_dump(Monitor *mon);
+/* True if incomming migration entered POSTCOPY_INCOMING_DISCARD */
+bool migration_in_incoming_postcopy(void);
/* migration/block-dirty-bitmap.c */
void dirty_bitmap_mig_init(void);
diff --git a/include/sysemu/balloon.h b/include/sysemu/balloon.h
index aea0c44985..20a2defe3a 100644
--- a/include/sysemu/balloon.h
+++ b/include/sysemu/balloon.h
@@ -23,7 +23,5 @@ typedef void (QEMUBalloonStatus)(void *opaque, BalloonInfo *info);
int qemu_add_balloon_handler(QEMUBalloonEvent *event_func,
QEMUBalloonStatus *stat_func, void *opaque);
void qemu_remove_balloon_handler(void *opaque);
-bool qemu_balloon_is_inhibited(void);
-void qemu_balloon_inhibit(bool state);
#endif
diff --git a/migration/migration.c b/migration/migration.c
index 481a590f72..d365d82209 100644
--- a/migration/migration.c
+++ b/migration/migration.c
@@ -1772,6 +1772,13 @@ bool migration_in_postcopy_after_devices(MigrationState *s)
return migration_in_postcopy() && s->postcopy_after_devices;
}
+bool migration_in_incoming_postcopy(void)
+{
+ PostcopyState ps = postcopy_state_get();
+
+ return ps >= POSTCOPY_INCOMING_DISCARD && ps < POSTCOPY_INCOMING_END;
+}
+
bool migration_is_idle(void)
{
MigrationState *s = current_migration;
diff --git a/migration/postcopy-ram.c b/migration/postcopy-ram.c
index a36402722b..b41a9fe2fd 100644
--- a/migration/postcopy-ram.c
+++ b/migration/postcopy-ram.c
@@ -27,7 +27,6 @@
#include "qemu/notify.h"
#include "qemu/rcu.h"
#include "sysemu/sysemu.h"
-#include "sysemu/balloon.h"
#include "qemu/error-report.h"
#include "trace.h"
#include "hw/boards.h"
@@ -520,20 +519,6 @@ int postcopy_ram_incoming_init(MigrationIncomingState *mis)
return 0;
}
-/*
- * Manage a single vote to the QEMU balloon inhibitor for all postcopy usage,
- * last caller wins.
- */
-static void postcopy_balloon_inhibit(bool state)
-{
- static bool cur_state = false;
-
- if (state != cur_state) {
- qemu_balloon_inhibit(state);
- cur_state = state;
- }
-}
-
/*
* At the end of a migration where postcopy_ram_incoming_init was called.
*/
@@ -565,8 +550,6 @@ int postcopy_ram_incoming_cleanup(MigrationIncomingState *mis)
mis->have_fault_thread = false;
}
- postcopy_balloon_inhibit(false);
-
if (enable_mlock) {
if (os_mlock() < 0) {
error_report("mlock: %s", strerror(errno));
@@ -1160,12 +1143,6 @@ int postcopy_ram_incoming_setup(MigrationIncomingState *mis)
}
memset(mis->postcopy_tmp_zero_page, '\0', mis->largest_page_size);
- /*
- * Ballooning can mark pages as absent while we're postcopying
- * that would cause false userfaults.
- */
- postcopy_balloon_inhibit(true);
-
trace_postcopy_ram_enable_notify();
return 0;
--
2.26.2
^ permalink raw reply related [flat|nested] 29+ messages in thread* [PATCH v5 07/21] target/i386: sev: Use ram_block_discard_disable()
2020-06-26 7:22 [PATCH v5 00/21] virtio-mem: Paravirtualized memory hot(un)plug David Hildenbrand
` (5 preceding siblings ...)
2020-06-26 7:22 ` [PATCH v5 06/21] virtio-balloon: Rip out qemu_balloon_inhibit() David Hildenbrand
@ 2020-06-26 7:22 ` David Hildenbrand
2020-06-26 7:22 ` [PATCH v5 08/21] migration/rdma: " David Hildenbrand
` (14 subsequent siblings)
21 siblings, 0 replies; 29+ messages in thread
From: David Hildenbrand @ 2020-06-26 7:22 UTC (permalink / raw)
To: qemu-devel
Cc: kvm, qemu-s390x, Richard Henderson, Paolo Bonzini,
Dr . David Alan Gilbert, Eduardo Habkost, Michael S . Tsirkin,
David Hildenbrand
AMD SEV will pin all guest memory, mark discarding of RAM broken. At the
time this is called, we cannot have anyone active that relies on discards
to work properly - let's still implement error handling.
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Cc: "Michael S. Tsirkin" <mst@redhat.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Richard Henderson <rth@twiddle.net>
Cc: Eduardo Habkost <ehabkost@redhat.com>
Signed-off-by: David Hildenbrand <david@redhat.com>
---
target/i386/sev.c | 7 +++++++
1 file changed, 7 insertions(+)
diff --git a/target/i386/sev.c b/target/i386/sev.c
index d273174ad3..f100a53231 100644
--- a/target/i386/sev.c
+++ b/target/i386/sev.c
@@ -680,6 +680,12 @@ sev_guest_init(const char *id)
uint32_t host_cbitpos;
struct sev_user_data_status status = {};
+ ret = ram_block_discard_disable(true);
+ if (ret) {
+ error_report("%s: cannot disable RAM discard", __func__);
+ return NULL;
+ }
+
sev = lookup_sev_guest_info(id);
if (!sev) {
error_report("%s: '%s' is not a valid '%s' object",
@@ -751,6 +757,7 @@ sev_guest_init(const char *id)
return sev;
err:
sev_guest = NULL;
+ ram_block_discard_disable(false);
return NULL;
}
--
2.26.2
^ permalink raw reply related [flat|nested] 29+ messages in thread* [PATCH v5 08/21] migration/rdma: Use ram_block_discard_disable()
2020-06-26 7:22 [PATCH v5 00/21] virtio-mem: Paravirtualized memory hot(un)plug David Hildenbrand
` (6 preceding siblings ...)
2020-06-26 7:22 ` [PATCH v5 07/21] target/i386: sev: Use ram_block_discard_disable() David Hildenbrand
@ 2020-06-26 7:22 ` David Hildenbrand
2020-06-26 7:22 ` [PATCH v5 09/21] migration/colo: " David Hildenbrand
` (13 subsequent siblings)
21 siblings, 0 replies; 29+ messages in thread
From: David Hildenbrand @ 2020-06-26 7:22 UTC (permalink / raw)
To: qemu-devel
Cc: kvm, qemu-s390x, Richard Henderson, Paolo Bonzini,
Dr . David Alan Gilbert, Eduardo Habkost, Michael S . Tsirkin,
David Hildenbrand, Juan Quintela
RDMA will pin all guest memory (as documented in docs/rdma.txt). We want
to disable RAM block discards - however, to keep it simple use
ram_block_discard_is_required() instead of inhibiting.
Note: It is not sufficient to limit disabling to pin_all. Even when only
conditionally pinning 1 MB chunks, as soon as one page within such a
chunk was discarded and one page not, the discarded pages will be pinned
as well.
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Cc: "Michael S. Tsirkin" <mst@redhat.com>
Cc: Juan Quintela <quintela@redhat.com>
Cc: "Dr. David Alan Gilbert" <dgilbert@redhat.com>
Signed-off-by: David Hildenbrand <david@redhat.com>
---
migration/rdma.c | 18 ++++++++++++++++--
1 file changed, 16 insertions(+), 2 deletions(-)
diff --git a/migration/rdma.c b/migration/rdma.c
index ec45d33ba3..bbe6f36627 100644
--- a/migration/rdma.c
+++ b/migration/rdma.c
@@ -29,6 +29,7 @@
#include "qemu/sockets.h"
#include "qemu/bitmap.h"
#include "qemu/coroutine.h"
+#include "exec/memory.h"
#include <sys/socket.h>
#include <netdb.h>
#include <arpa/inet.h>
@@ -4017,8 +4018,14 @@ void rdma_start_incoming_migration(const char *host_port, Error **errp)
Error *local_err = NULL;
trace_rdma_start_incoming_migration();
- rdma = qemu_rdma_data_init(host_port, &local_err);
+ /* Avoid ram_block_discard_disable(), cannot change during migration. */
+ if (ram_block_discard_is_required()) {
+ error_setg(errp, "RDMA: cannot disable RAM discard");
+ return;
+ }
+
+ rdma = qemu_rdma_data_init(host_port, &local_err);
if (rdma == NULL) {
goto err;
}
@@ -4067,10 +4074,17 @@ void rdma_start_outgoing_migration(void *opaque,
const char *host_port, Error **errp)
{
MigrationState *s = opaque;
- RDMAContext *rdma = qemu_rdma_data_init(host_port, errp);
RDMAContext *rdma_return_path = NULL;
+ RDMAContext *rdma;
int ret = 0;
+ /* Avoid ram_block_discard_disable(), cannot change during migration. */
+ if (ram_block_discard_is_required()) {
+ error_setg(errp, "RDMA: cannot disable RAM discard");
+ return;
+ }
+
+ rdma = qemu_rdma_data_init(host_port, errp);
if (rdma == NULL) {
goto err;
}
--
2.26.2
^ permalink raw reply related [flat|nested] 29+ messages in thread* [PATCH v5 09/21] migration/colo: Use ram_block_discard_disable()
2020-06-26 7:22 [PATCH v5 00/21] virtio-mem: Paravirtualized memory hot(un)plug David Hildenbrand
` (7 preceding siblings ...)
2020-06-26 7:22 ` [PATCH v5 08/21] migration/rdma: " David Hildenbrand
@ 2020-06-26 7:22 ` David Hildenbrand
2020-06-26 7:22 ` [PATCH v5 10/21] virtio-mem: Paravirtualized memory hot(un)plug David Hildenbrand
` (12 subsequent siblings)
21 siblings, 0 replies; 29+ messages in thread
From: David Hildenbrand @ 2020-06-26 7:22 UTC (permalink / raw)
To: qemu-devel
Cc: kvm, qemu-s390x, Richard Henderson, Paolo Bonzini,
Dr . David Alan Gilbert, Eduardo Habkost, Michael S . Tsirkin,
David Hildenbrand, Lukas Straub, Hailiang Zhang, Juan Quintela
COLO will copy all memory in a RAM block, disable discarding of RAM.
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Tested-by: Lukas Straub <lukasstraub2@web.de>
Cc: "Michael S. Tsirkin" <mst@redhat.com>
Cc: Hailiang Zhang <zhang.zhanghailiang@huawei.com>
Cc: Juan Quintela <quintela@redhat.com>
Cc: "Dr. David Alan Gilbert" <dgilbert@redhat.com>
Signed-off-by: David Hildenbrand <david@redhat.com>
---
include/migration/colo.h | 2 +-
migration/migration.c | 8 +++++++-
migration/savevm.c | 11 +++++++++--
3 files changed, 17 insertions(+), 4 deletions(-)
diff --git a/include/migration/colo.h b/include/migration/colo.h
index 1636e6f907..768e1f04c3 100644
--- a/include/migration/colo.h
+++ b/include/migration/colo.h
@@ -25,7 +25,7 @@ void migrate_start_colo_process(MigrationState *s);
bool migration_in_colo_state(void);
/* loadvm */
-void migration_incoming_enable_colo(void);
+int migration_incoming_enable_colo(void);
void migration_incoming_disable_colo(void);
bool migration_incoming_colo_enabled(void);
void *colo_process_incoming_thread(void *opaque);
diff --git a/migration/migration.c b/migration/migration.c
index d365d82209..92e44e021e 100644
--- a/migration/migration.c
+++ b/migration/migration.c
@@ -338,12 +338,18 @@ bool migration_incoming_colo_enabled(void)
void migration_incoming_disable_colo(void)
{
+ ram_block_discard_disable(false);
migration_colo_enabled = false;
}
-void migration_incoming_enable_colo(void)
+int migration_incoming_enable_colo(void)
{
+ if (ram_block_discard_disable(true)) {
+ error_report("COLO: cannot disable RAM discard");
+ return -EBUSY;
+ }
migration_colo_enabled = true;
+ return 0;
}
void migrate_add_address(SocketAddress *address)
diff --git a/migration/savevm.c b/migration/savevm.c
index b979ea6e7f..6e01724605 100644
--- a/migration/savevm.c
+++ b/migration/savevm.c
@@ -2111,8 +2111,15 @@ static int loadvm_handle_recv_bitmap(MigrationIncomingState *mis,
static int loadvm_process_enable_colo(MigrationIncomingState *mis)
{
- migration_incoming_enable_colo();
- return colo_init_ram_cache();
+ int ret = migration_incoming_enable_colo();
+
+ if (!ret) {
+ ret = colo_init_ram_cache();
+ if (ret) {
+ migration_incoming_disable_colo();
+ }
+ }
+ return ret;
}
/*
--
2.26.2
^ permalink raw reply related [flat|nested] 29+ messages in thread* [PATCH v5 10/21] virtio-mem: Paravirtualized memory hot(un)plug
2020-06-26 7:22 [PATCH v5 00/21] virtio-mem: Paravirtualized memory hot(un)plug David Hildenbrand
` (8 preceding siblings ...)
2020-06-26 7:22 ` [PATCH v5 09/21] migration/colo: " David Hildenbrand
@ 2020-06-26 7:22 ` David Hildenbrand
2020-06-30 10:06 ` Michael S. Tsirkin
2020-06-26 7:22 ` [PATCH v5 11/21] virtio-pci: Proxy for virtio-mem David Hildenbrand
` (11 subsequent siblings)
21 siblings, 1 reply; 29+ messages in thread
From: David Hildenbrand @ 2020-06-26 7:22 UTC (permalink / raw)
To: qemu-devel
Cc: kvm, qemu-s390x, Richard Henderson, Paolo Bonzini,
Dr . David Alan Gilbert, Eduardo Habkost, Michael S . Tsirkin,
David Hildenbrand, Eric Blake, Markus Armbruster, Igor Mammedov
This is the very basic/initial version of virtio-mem. An introduction to
virtio-mem can be found in the Linux kernel driver [1]. While it can be
used in the current state for hotplug of a smaller amount of memory, it
will heavily benefit from resizeable memory regions in the future.
Each virtio-mem device manages a memory region (provided via a memory
backend). After requested by the hypervisor ("requested-size"), the
guest can try to plug/unplug blocks of memory within that region, in order
to reach the requested size. Initially, and after a reboot, all memory is
unplugged (except in special cases - reboot during postcopy).
The guest may only try to plug/unplug blocks of memory within the usable
region size. The usable region size is a little bigger than the
requested size, to give the device driver some flexibility. The usable
region size will only grow, except on reboots or when all memory is
requested to get unplugged. The guest can never plug more memory than
requested. Unplugged memory will get zapped/discarded, similar to in a
balloon device.
The block size is variable, however, it is always chosen in a way such that
THP splits are avoided (e.g., 2MB). The state of each block
(plugged/unplugged) is tracked in a bitmap.
As virtio-mem devices (e.g., virtio-mem-pci) will be memory devices, we now
expose "VirtioMEMDeviceInfo" via "query-memory-devices".
--------------------------------------------------------------------------
There are two important follow-up items that are in the works:
1. Resizeable memory regions: Use resizeable allocations/RAM blocks to
grow/shrink along with the usable region size. This avoids creating
initially very big VMAs, RAM blocks, and KVM slots.
2. Protection of unplugged memory: Make sure the gust cannot actually
make use of unplugged memory.
Other follow-up items that are in the works:
1. Exclude unplugged memory during migration (via precopy notifier).
2. Handle remapping of memory.
3. Support for other architectures.
--------------------------------------------------------------------------
Example usage (virtio-mem-pci is introduced in follow-up patches):
Start QEMU with two virtio-mem devices (one per NUMA node):
$ qemu-system-x86_64 -m 4G,maxmem=20G \
-smp sockets=2,cores=2 \
-numa node,nodeid=0,cpus=0-1 -numa node,nodeid=1,cpus=2-3 \
[...]
-object memory-backend-ram,id=mem0,size=8G \
-device virtio-mem-pci,id=vm0,memdev=mem0,node=0,requested-size=0M \
-object memory-backend-ram,id=mem1,size=8G \
-device virtio-mem-pci,id=vm1,memdev=mem1,node=1,requested-size=1G
Query the configuration:
(qemu) info memory-devices
Memory device [virtio-mem]: "vm0"
memaddr: 0x140000000
node: 0
requested-size: 0
size: 0
max-size: 8589934592
block-size: 2097152
memdev: /objects/mem0
Memory device [virtio-mem]: "vm1"
memaddr: 0x340000000
node: 1
requested-size: 1073741824
size: 1073741824
max-size: 8589934592
block-size: 2097152
memdev: /objects/mem1
Add some memory to node 0:
(qemu) qom-set vm0 requested-size 500M
Remove some memory from node 1:
(qemu) qom-set vm1 requested-size 200M
Query the configuration again:
(qemu) info memory-devices
Memory device [virtio-mem]: "vm0"
memaddr: 0x140000000
node: 0
requested-size: 524288000
size: 524288000
max-size: 8589934592
block-size: 2097152
memdev: /objects/mem0
Memory device [virtio-mem]: "vm1"
memaddr: 0x340000000
node: 1
requested-size: 209715200
size: 209715200
max-size: 8589934592
block-size: 2097152
memdev: /objects/mem1
[1] https://lkml.kernel.org/r/20200311171422.10484-1-david@redhat.com
Cc: "Michael S. Tsirkin" <mst@redhat.com>
Cc: Eric Blake <eblake@redhat.com>
Cc: Markus Armbruster <armbru@redhat.com>
Cc: "Dr. David Alan Gilbert" <dgilbert@redhat.com>
Cc: Igor Mammedov <imammedo@redhat.com>
Signed-off-by: David Hildenbrand <david@redhat.com>
---
hw/virtio/Kconfig | 11 +
hw/virtio/Makefile.objs | 1 +
hw/virtio/virtio-mem.c | 724 +++++++++++++++++++++++++++++++++
include/hw/virtio/virtio-mem.h | 78 ++++
qapi/misc.json | 39 +-
5 files changed, 852 insertions(+), 1 deletion(-)
create mode 100644 hw/virtio/virtio-mem.c
create mode 100644 include/hw/virtio/virtio-mem.h
diff --git a/hw/virtio/Kconfig b/hw/virtio/Kconfig
index 83122424fa..0eda25c4e1 100644
--- a/hw/virtio/Kconfig
+++ b/hw/virtio/Kconfig
@@ -47,3 +47,14 @@ config VIRTIO_PMEM
depends on VIRTIO
depends on VIRTIO_PMEM_SUPPORTED
select MEM_DEVICE
+
+config VIRTIO_MEM_SUPPORTED
+ bool
+
+config VIRTIO_MEM
+ bool
+ default y
+ depends on VIRTIO
+ depends on LINUX
+ depends on VIRTIO_MEM_SUPPORTED
+ select MEM_DEVICE
diff --git a/hw/virtio/Makefile.objs b/hw/virtio/Makefile.objs
index 13e75f171f..f3a65e01b7 100644
--- a/hw/virtio/Makefile.objs
+++ b/hw/virtio/Makefile.objs
@@ -19,6 +19,7 @@ obj-$(call land,$(CONFIG_VHOST_USER_FS),$(CONFIG_VIRTIO_PCI)) += vhost-user-fs-p
obj-$(CONFIG_VIRTIO_IOMMU) += virtio-iommu.o
obj-$(CONFIG_VHOST_VSOCK) += vhost-vsock-common.o vhost-vsock.o
obj-$(CONFIG_VHOST_USER_VSOCK) += vhost-vsock-common.o vhost-user-vsock.o
+obj-$(CONFIG_VIRTIO_MEM) += virtio-mem.o
ifeq ($(CONFIG_VIRTIO_PCI),y)
obj-$(CONFIG_VHOST_VSOCK) += vhost-vsock-pci.o
diff --git a/hw/virtio/virtio-mem.c b/hw/virtio/virtio-mem.c
new file mode 100644
index 0000000000..d8a0c974d3
--- /dev/null
+++ b/hw/virtio/virtio-mem.c
@@ -0,0 +1,724 @@
+/*
+ * Virtio MEM device
+ *
+ * Copyright (C) 2020 Red Hat, Inc.
+ *
+ * Authors:
+ * David Hildenbrand <david@redhat.com>
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2.
+ * See the COPYING file in the top-level directory.
+ */
+
+#include "qemu/osdep.h"
+#include "qemu-common.h"
+#include "qemu/iov.h"
+#include "qemu/cutils.h"
+#include "qemu/error-report.h"
+#include "qemu/units.h"
+#include "sysemu/numa.h"
+#include "sysemu/sysemu.h"
+#include "sysemu/reset.h"
+#include "hw/virtio/virtio.h"
+#include "hw/virtio/virtio-bus.h"
+#include "hw/virtio/virtio-access.h"
+#include "hw/virtio/virtio-mem.h"
+#include "qapi/error.h"
+#include "qapi/visitor.h"
+#include "exec/ram_addr.h"
+#include "migration/misc.h"
+#include "hw/boards.h"
+#include "hw/qdev-properties.h"
+#include "config-devices.h"
+
+/*
+ * Use QEMU_VMALLOC_ALIGN, so no THP will have to be split when unplugging
+ * memory (e.g., 2MB on x86_64).
+ */
+#define VIRTIO_MEM_MIN_BLOCK_SIZE QEMU_VMALLOC_ALIGN
+/*
+ * Size the usable region bigger than the requested size if possible. Esp.
+ * Linux guests will only add (aligned) memory blocks in case they fully
+ * fit into the usable region, but plug+online only a subset of the pages.
+ * The memory block size corresponds mostly to the section size.
+ *
+ * This allows e.g., to add 20MB with a section size of 128MB on x86_64, and
+ * a section size of 1GB on arm64 (as long as the start address is properly
+ * aligned, similar to ordinary DIMMs).
+ *
+ * We can change this at any time and maybe even make it configurable if
+ * necessary (as the section size can change). But it's more likely that the
+ * section size will rather get smaller and not bigger over time.
+ */
+#if defined(__x86_64__)
+#define VIRTIO_MEM_USABLE_EXTENT (2 * (128 * MiB))
+#else
+#error VIRTIO_MEM_USABLE_EXTENT not defined
+#endif
+
+static bool virtio_mem_is_busy(void)
+{
+ /*
+ * Postcopy cannot handle concurrent discards and we don't want to migrate
+ * pages on-demand with stale content when plugging new blocks.
+ */
+ return migration_in_incoming_postcopy();
+}
+
+static bool virtio_mem_test_bitmap(VirtIOMEM *vmem, uint64_t start_gpa,
+ uint64_t size, bool plugged)
+{
+ const unsigned long first_bit = (start_gpa - vmem->addr) / vmem->block_size;
+ const unsigned long last_bit = first_bit + (size / vmem->block_size) - 1;
+ unsigned long found_bit;
+
+ /* We fake a shorter bitmap to avoid searching too far. */
+ if (plugged) {
+ found_bit = find_next_zero_bit(vmem->bitmap, last_bit + 1, first_bit);
+ } else {
+ found_bit = find_next_bit(vmem->bitmap, last_bit + 1, first_bit);
+ }
+ return found_bit > last_bit;
+}
+
+static void virtio_mem_set_bitmap(VirtIOMEM *vmem, uint64_t start_gpa,
+ uint64_t size, bool plugged)
+{
+ const unsigned long bit = (start_gpa - vmem->addr) / vmem->block_size;
+ const unsigned long nbits = size / vmem->block_size;
+
+ if (plugged) {
+ bitmap_set(vmem->bitmap, bit, nbits);
+ } else {
+ bitmap_clear(vmem->bitmap, bit, nbits);
+ }
+}
+
+static void virtio_mem_send_response(VirtIOMEM *vmem, VirtQueueElement *elem,
+ struct virtio_mem_resp *resp)
+{
+ VirtIODevice *vdev = VIRTIO_DEVICE(vmem);
+ VirtQueue *vq = vmem->vq;
+
+ iov_from_buf(elem->in_sg, elem->in_num, 0, resp, sizeof(*resp));
+
+ virtqueue_push(vq, elem, sizeof(*resp));
+ virtio_notify(vdev, vq);
+}
+
+static void virtio_mem_send_response_simple(VirtIOMEM *vmem,
+ VirtQueueElement *elem,
+ uint16_t type)
+{
+ struct virtio_mem_resp resp = {
+ .type = cpu_to_le16(type),
+ };
+
+ virtio_mem_send_response(vmem, elem, &resp);
+}
+
+static bool virtio_mem_valid_range(VirtIOMEM *vmem, uint64_t gpa, uint64_t size)
+{
+ if (!QEMU_IS_ALIGNED(gpa, vmem->block_size)) {
+ return false;
+ }
+ if (gpa + size < gpa || !size) {
+ return false;
+ }
+ if (gpa < vmem->addr || gpa >= vmem->addr + vmem->usable_region_size) {
+ return false;
+ }
+ if (gpa + size > vmem->addr + vmem->usable_region_size) {
+ return false;
+ }
+ return true;
+}
+
+static int virtio_mem_set_block_state(VirtIOMEM *vmem, uint64_t start_gpa,
+ uint64_t size, bool plug)
+{
+ const uint64_t offset = start_gpa - vmem->addr;
+ int ret;
+
+ if (virtio_mem_is_busy()) {
+ return -EBUSY;
+ }
+
+ if (!plug) {
+ ret = ram_block_discard_range(vmem->memdev->mr.ram_block, offset, size);
+ if (ret) {
+ error_report("Unexpected error discarding RAM: %s",
+ strerror(-ret));
+ return -EBUSY;
+ }
+ }
+ virtio_mem_set_bitmap(vmem, start_gpa, size, plug);
+ return 0;
+}
+
+static int virtio_mem_state_change_request(VirtIOMEM *vmem, uint64_t gpa,
+ uint16_t nb_blocks, bool plug)
+{
+ const uint64_t size = nb_blocks * vmem->block_size;
+ int ret;
+
+ if (!virtio_mem_valid_range(vmem, gpa, size)) {
+ return VIRTIO_MEM_RESP_ERROR;
+ }
+
+ if (plug && (vmem->size + size > vmem->requested_size)) {
+ return VIRTIO_MEM_RESP_NACK;
+ }
+
+ /* test if really all blocks are in the opposite state */
+ if (!virtio_mem_test_bitmap(vmem, gpa, size, !plug)) {
+ return VIRTIO_MEM_RESP_ERROR;
+ }
+
+ ret = virtio_mem_set_block_state(vmem, gpa, size, plug);
+ if (ret) {
+ return VIRTIO_MEM_RESP_BUSY;
+ }
+ if (plug) {
+ vmem->size += size;
+ } else {
+ vmem->size -= size;
+ }
+ return VIRTIO_MEM_RESP_ACK;
+}
+
+static void virtio_mem_plug_request(VirtIOMEM *vmem, VirtQueueElement *elem,
+ struct virtio_mem_req *req)
+{
+ const uint64_t gpa = le64_to_cpu(req->u.plug.addr);
+ const uint16_t nb_blocks = le16_to_cpu(req->u.plug.nb_blocks);
+ uint16_t type;
+
+ type = virtio_mem_state_change_request(vmem, gpa, nb_blocks, true);
+ virtio_mem_send_response_simple(vmem, elem, type);
+}
+
+static void virtio_mem_unplug_request(VirtIOMEM *vmem, VirtQueueElement *elem,
+ struct virtio_mem_req *req)
+{
+ const uint64_t gpa = le64_to_cpu(req->u.unplug.addr);
+ const uint16_t nb_blocks = le16_to_cpu(req->u.unplug.nb_blocks);
+ uint16_t type;
+
+ type = virtio_mem_state_change_request(vmem, gpa, nb_blocks, false);
+ virtio_mem_send_response_simple(vmem, elem, type);
+}
+
+static void virtio_mem_resize_usable_region(VirtIOMEM *vmem,
+ uint64_t requested_size,
+ bool can_shrink)
+{
+ uint64_t newsize = MIN(memory_region_size(&vmem->memdev->mr),
+ requested_size + VIRTIO_MEM_USABLE_EXTENT);
+
+ if (!requested_size) {
+ newsize = 0;
+ }
+
+ if (newsize < vmem->usable_region_size && !can_shrink) {
+ return;
+ }
+
+ vmem->usable_region_size = newsize;
+}
+
+static int virtio_mem_unplug_all(VirtIOMEM *vmem)
+{
+ RAMBlock *rb = vmem->memdev->mr.ram_block;
+ int ret;
+
+ if (virtio_mem_is_busy()) {
+ return -EBUSY;
+ }
+
+ ret = ram_block_discard_range(rb, 0, qemu_ram_get_used_length(rb));
+ if (ret) {
+ error_report("Unexpected error discarding RAM: %s", strerror(-ret));
+ return -EBUSY;
+ }
+ bitmap_clear(vmem->bitmap, 0, vmem->bitmap_size);
+ vmem->size = 0;
+
+ virtio_mem_resize_usable_region(vmem, vmem->requested_size, true);
+ return 0;
+}
+
+static void virtio_mem_unplug_all_request(VirtIOMEM *vmem,
+ VirtQueueElement *elem)
+{
+ if (virtio_mem_unplug_all(vmem)) {
+ virtio_mem_send_response_simple(vmem, elem, VIRTIO_MEM_RESP_BUSY);
+ } else {
+ virtio_mem_send_response_simple(vmem, elem, VIRTIO_MEM_RESP_ACK);
+ }
+}
+
+static void virtio_mem_state_request(VirtIOMEM *vmem, VirtQueueElement *elem,
+ struct virtio_mem_req *req)
+{
+ const uint16_t nb_blocks = le16_to_cpu(req->u.state.nb_blocks);
+ const uint64_t gpa = le64_to_cpu(req->u.state.addr);
+ const uint64_t size = nb_blocks * vmem->block_size;
+ struct virtio_mem_resp resp = {
+ .type = cpu_to_le16(VIRTIO_MEM_RESP_ACK),
+ };
+
+ if (!virtio_mem_valid_range(vmem, gpa, size)) {
+ virtio_mem_send_response_simple(vmem, elem, VIRTIO_MEM_RESP_ERROR);
+ return;
+ }
+
+ if (virtio_mem_test_bitmap(vmem, gpa, size, true)) {
+ resp.u.state.state = cpu_to_le16(VIRTIO_MEM_STATE_PLUGGED);
+ } else if (virtio_mem_test_bitmap(vmem, gpa, size, false)) {
+ resp.u.state.state = cpu_to_le16(VIRTIO_MEM_STATE_UNPLUGGED);
+ } else {
+ resp.u.state.state = cpu_to_le16(VIRTIO_MEM_STATE_MIXED);
+ }
+ virtio_mem_send_response(vmem, elem, &resp);
+}
+
+static void virtio_mem_handle_request(VirtIODevice *vdev, VirtQueue *vq)
+{
+ const int len = sizeof(struct virtio_mem_req);
+ VirtIOMEM *vmem = VIRTIO_MEM(vdev);
+ VirtQueueElement *elem;
+ struct virtio_mem_req req;
+ uint16_t type;
+
+ while (true) {
+ elem = virtqueue_pop(vq, sizeof(VirtQueueElement));
+ if (!elem) {
+ return;
+ }
+
+ if (iov_to_buf(elem->out_sg, elem->out_num, 0, &req, len) < len) {
+ virtio_error(vdev, "virtio-mem protocol violation: invalid request"
+ " size: %d", len);
+ g_free(elem);
+ return;
+ }
+
+ if (iov_size(elem->in_sg, elem->in_num) <
+ sizeof(struct virtio_mem_resp)) {
+ virtio_error(vdev, "virtio-mem protocol violation: not enough space"
+ " for response: %zu",
+ iov_size(elem->in_sg, elem->in_num));
+ g_free(elem);
+ return;
+ }
+
+ type = le16_to_cpu(req.type);
+ switch (type) {
+ case VIRTIO_MEM_REQ_PLUG:
+ virtio_mem_plug_request(vmem, elem, &req);
+ break;
+ case VIRTIO_MEM_REQ_UNPLUG:
+ virtio_mem_unplug_request(vmem, elem, &req);
+ break;
+ case VIRTIO_MEM_REQ_UNPLUG_ALL:
+ virtio_mem_unplug_all_request(vmem, elem);
+ break;
+ case VIRTIO_MEM_REQ_STATE:
+ virtio_mem_state_request(vmem, elem, &req);
+ break;
+ default:
+ virtio_error(vdev, "virtio-mem protocol violation: unknown request"
+ " type: %d", type);
+ g_free(elem);
+ return;
+ }
+
+ g_free(elem);
+ }
+}
+
+static void virtio_mem_get_config(VirtIODevice *vdev, uint8_t *config_data)
+{
+ VirtIOMEM *vmem = VIRTIO_MEM(vdev);
+ struct virtio_mem_config *config = (void *) config_data;
+
+ config->block_size = cpu_to_le64(vmem->block_size);
+ config->node_id = cpu_to_le16(vmem->node);
+ config->requested_size = cpu_to_le64(vmem->requested_size);
+ config->plugged_size = cpu_to_le64(vmem->size);
+ config->addr = cpu_to_le64(vmem->addr);
+ config->region_size = cpu_to_le64(memory_region_size(&vmem->memdev->mr));
+ config->usable_region_size = cpu_to_le64(vmem->usable_region_size);
+}
+
+static uint64_t virtio_mem_get_features(VirtIODevice *vdev, uint64_t features,
+ Error **errp)
+{
+ MachineState *ms = MACHINE(qdev_get_machine());
+
+ if (ms->numa_state) {
+#if defined(CONFIG_ACPI)
+ virtio_add_feature(&features, VIRTIO_MEM_F_ACPI_PXM);
+#endif
+ }
+ return features;
+}
+
+static void virtio_mem_system_reset(void *opaque)
+{
+ VirtIOMEM *vmem = VIRTIO_MEM(opaque);
+
+ /*
+ * During usual resets, we will unplug all memory and shrink the usable
+ * region size. This is, however, not possible in all scenarios. Then,
+ * the guest has to deal with this manually (VIRTIO_MEM_REQ_UNPLUG_ALL).
+ */
+ virtio_mem_unplug_all(vmem);
+}
+
+static void virtio_mem_device_realize(DeviceState *dev, Error **errp)
+{
+ MachineState *ms = MACHINE(qdev_get_machine());
+ int nb_numa_nodes = ms->numa_state ? ms->numa_state->num_nodes : 0;
+ VirtIODevice *vdev = VIRTIO_DEVICE(dev);
+ VirtIOMEM *vmem = VIRTIO_MEM(dev);
+ uint64_t page_size;
+ RAMBlock *rb;
+ int ret;
+
+ if (!vmem->memdev) {
+ error_setg(errp, "'%s' property is not set", VIRTIO_MEM_MEMDEV_PROP);
+ return;
+ } else if (host_memory_backend_is_mapped(vmem->memdev)) {
+ char *path = object_get_canonical_path_component(OBJECT(vmem->memdev));
+
+ error_setg(errp, "'%s' property specifies a busy memdev: %s",
+ VIRTIO_MEM_MEMDEV_PROP, path);
+ g_free(path);
+ return;
+ } else if (!memory_region_is_ram(&vmem->memdev->mr) ||
+ memory_region_is_rom(&vmem->memdev->mr) ||
+ !vmem->memdev->mr.ram_block) {
+ error_setg(errp, "'%s' property specifies an unsupported memdev",
+ VIRTIO_MEM_MEMDEV_PROP);
+ return;
+ }
+
+ if ((nb_numa_nodes && vmem->node >= nb_numa_nodes) ||
+ (!nb_numa_nodes && vmem->node)) {
+ error_setg(errp, "'%s' property has value '%" PRIu32 "', which exceeds"
+ "the number of numa nodes: %d", VIRTIO_MEM_NODE_PROP,
+ vmem->node, nb_numa_nodes ? nb_numa_nodes : 1);
+ return;
+ }
+
+ if (enable_mlock) {
+ error_setg(errp, "Incompatible with mlock");
+ return;
+ }
+
+ rb = vmem->memdev->mr.ram_block;
+ page_size = qemu_ram_pagesize(rb);
+
+ if (vmem->block_size < page_size) {
+ error_setg(errp, "'%s' property has to be at least the page size (0x%"
+ PRIx64 ")", VIRTIO_MEM_BLOCK_SIZE_PROP, page_size);
+ return;
+ } else if (!QEMU_IS_ALIGNED(vmem->requested_size, vmem->block_size)) {
+ error_setg(errp, "'%s' property has to be multiples of '%s' (0x%" PRIx64
+ ")", VIRTIO_MEM_REQUESTED_SIZE_PROP,
+ VIRTIO_MEM_BLOCK_SIZE_PROP, vmem->block_size);
+ return;
+ } else if (!QEMU_IS_ALIGNED(memory_region_size(&vmem->memdev->mr),
+ vmem->block_size)) {
+ error_setg(errp, "'%s' property memdev size has to be multiples of"
+ "'%s' (0x%" PRIx64 ")", VIRTIO_MEM_MEMDEV_PROP,
+ VIRTIO_MEM_BLOCK_SIZE_PROP, vmem->block_size);
+ return;
+ }
+
+ if (ram_block_discard_require(true)) {
+ error_setg(errp, "Discarding RAM is disabled");
+ return;
+ }
+
+ ret = ram_block_discard_range(rb, 0, qemu_ram_get_used_length(rb));
+ if (ret) {
+ error_setg_errno(errp, -ret, "Unexpected error discarding RAM");
+ ram_block_discard_require(false);
+ return;
+ }
+
+ virtio_mem_resize_usable_region(vmem, vmem->requested_size, true);
+
+ vmem->bitmap_size = memory_region_size(&vmem->memdev->mr) /
+ vmem->block_size;
+ vmem->bitmap = bitmap_new(vmem->bitmap_size);
+
+ virtio_init(vdev, TYPE_VIRTIO_MEM, VIRTIO_ID_MEM,
+ sizeof(struct virtio_mem_config));
+ vmem->vq = virtio_add_queue(vdev, 128, virtio_mem_handle_request);
+
+ host_memory_backend_set_mapped(vmem->memdev, true);
+ vmstate_register_ram(&vmem->memdev->mr, DEVICE(vmem));
+ qemu_register_reset(virtio_mem_system_reset, vmem);
+}
+
+static void virtio_mem_device_unrealize(DeviceState *dev)
+{
+ VirtIODevice *vdev = VIRTIO_DEVICE(dev);
+ VirtIOMEM *vmem = VIRTIO_MEM(dev);
+
+ qemu_unregister_reset(virtio_mem_system_reset, vmem);
+ vmstate_unregister_ram(&vmem->memdev->mr, DEVICE(vmem));
+ host_memory_backend_set_mapped(vmem->memdev, false);
+ virtio_del_queue(vdev, 0);
+ virtio_cleanup(vdev);
+ g_free(vmem->bitmap);
+ ram_block_discard_require(false);
+}
+
+static int virtio_mem_restore_unplugged(VirtIOMEM *vmem)
+{
+ RAMBlock *rb = vmem->memdev->mr.ram_block;
+ unsigned long first_zero_bit, last_zero_bit;
+ uint64_t offset, length;
+ int ret;
+
+ /* Find consecutive unplugged blocks and discard the consecutive range. */
+ first_zero_bit = find_first_zero_bit(vmem->bitmap, vmem->bitmap_size);
+ while (first_zero_bit < vmem->bitmap_size) {
+ offset = first_zero_bit * vmem->block_size;
+ last_zero_bit = find_next_bit(vmem->bitmap, vmem->bitmap_size,
+ first_zero_bit + 1) - 1;
+ length = (last_zero_bit - first_zero_bit + 1) * vmem->block_size;
+
+ ret = ram_block_discard_range(rb, offset, length);
+ if (ret) {
+ error_report("Unexpected error discarding RAM: %s",
+ strerror(-ret));
+ return -EINVAL;
+ }
+ first_zero_bit = find_next_zero_bit(vmem->bitmap, vmem->bitmap_size,
+ last_zero_bit + 2);
+ }
+ return 0;
+}
+
+static int virtio_mem_post_load(void *opaque, int version_id)
+{
+ if (migration_in_incoming_postcopy()) {
+ return 0;
+ }
+
+ return virtio_mem_restore_unplugged(VIRTIO_MEM(opaque));
+}
+
+static const VMStateDescription vmstate_virtio_mem_device = {
+ .name = "virtio-mem-device",
+ .minimum_version_id = 1,
+ .version_id = 1,
+ .post_load = virtio_mem_post_load,
+ .fields = (VMStateField[]) {
+ VMSTATE_UINT64(usable_region_size, VirtIOMEM),
+ VMSTATE_UINT64(size, VirtIOMEM),
+ VMSTATE_UINT64(requested_size, VirtIOMEM),
+ VMSTATE_BITMAP(bitmap, VirtIOMEM, 0, bitmap_size),
+ VMSTATE_END_OF_LIST()
+ },
+};
+
+static const VMStateDescription vmstate_virtio_mem = {
+ .name = "virtio-mem",
+ .minimum_version_id = 1,
+ .version_id = 1,
+ .fields = (VMStateField[]) {
+ VMSTATE_VIRTIO_DEVICE,
+ VMSTATE_END_OF_LIST()
+ },
+};
+
+static void virtio_mem_fill_device_info(const VirtIOMEM *vmem,
+ VirtioMEMDeviceInfo *vi)
+{
+ vi->memaddr = vmem->addr;
+ vi->node = vmem->node;
+ vi->requested_size = vmem->requested_size;
+ vi->size = vmem->size;
+ vi->max_size = memory_region_size(&vmem->memdev->mr);
+ vi->block_size = vmem->block_size;
+ vi->memdev = object_get_canonical_path(OBJECT(vmem->memdev));
+}
+
+static MemoryRegion *virtio_mem_get_memory_region(VirtIOMEM *vmem, Error **errp)
+{
+ if (!vmem->memdev) {
+ error_setg(errp, "'%s' property must be set", VIRTIO_MEM_MEMDEV_PROP);
+ return NULL;
+ }
+
+ return &vmem->memdev->mr;
+}
+
+static void virtio_mem_get_size(Object *obj, Visitor *v, const char *name,
+ void *opaque, Error **errp)
+{
+ const VirtIOMEM *vmem = VIRTIO_MEM(obj);
+ uint64_t value = vmem->size;
+
+ visit_type_size(v, name, &value, errp);
+}
+
+static void virtio_mem_get_requested_size(Object *obj, Visitor *v,
+ const char *name, void *opaque,
+ Error **errp)
+{
+ const VirtIOMEM *vmem = VIRTIO_MEM(obj);
+ uint64_t value = vmem->requested_size;
+
+ visit_type_size(v, name, &value, errp);
+}
+
+static void virtio_mem_set_requested_size(Object *obj, Visitor *v,
+ const char *name, void *opaque,
+ Error **errp)
+{
+ VirtIOMEM *vmem = VIRTIO_MEM(obj);
+ Error *err = NULL;
+ uint64_t value;
+
+ visit_type_size(v, name, &value, &err);
+ if (err) {
+ error_propagate(errp, err);
+ return;
+ }
+
+ /*
+ * The block size and memory backend are not fixed until the device was
+ * realized. realize() will verify these properties then.
+ */
+ if (DEVICE(obj)->realized) {
+ if (!QEMU_IS_ALIGNED(value, vmem->block_size)) {
+ error_setg(errp, "'%s' has to be multiples of '%s' (0x%" PRIx64
+ ")", name, VIRTIO_MEM_BLOCK_SIZE_PROP,
+ vmem->block_size);
+ return;
+ } else if (value > memory_region_size(&vmem->memdev->mr)) {
+ error_setg(errp, "'%s' cannot exceed the memory backend size"
+ "(0x%" PRIx64 ")", name,
+ memory_region_size(&vmem->memdev->mr));
+ return;
+ }
+
+ if (value != vmem->requested_size) {
+ virtio_mem_resize_usable_region(vmem, value, false);
+ vmem->requested_size = value;
+ }
+ /*
+ * Trigger a config update so the guest gets notified. We trigger
+ * even if the size didn't change (especially helpful for debugging).
+ */
+ virtio_notify_config(VIRTIO_DEVICE(vmem));
+ } else {
+ vmem->requested_size = value;
+ }
+}
+
+static void virtio_mem_get_block_size(Object *obj, Visitor *v, const char *name,
+ void *opaque, Error **errp)
+{
+ const VirtIOMEM *vmem = VIRTIO_MEM(obj);
+ uint64_t value = vmem->block_size;
+
+ visit_type_size(v, name, &value, errp);
+}
+
+static void virtio_mem_set_block_size(Object *obj, Visitor *v, const char *name,
+ void *opaque, Error **errp)
+{
+ VirtIOMEM *vmem = VIRTIO_MEM(obj);
+ Error *err = NULL;
+ uint64_t value;
+
+ if (DEVICE(obj)->realized) {
+ error_setg(errp, "'%s' cannot be changed", name);
+ return;
+ }
+
+ visit_type_size(v, name, &value, &err);
+ if (err) {
+ error_propagate(errp, err);
+ return;
+ }
+
+ if (value < VIRTIO_MEM_MIN_BLOCK_SIZE) {
+ error_setg(errp, "'%s' property has to be at least 0x%" PRIx32, name,
+ VIRTIO_MEM_MIN_BLOCK_SIZE);
+ return;
+ } else if (!is_power_of_2(value)) {
+ error_setg(errp, "'%s' property has to be a power of two", name);
+ return;
+ }
+ vmem->block_size = value;
+}
+
+static void virtio_mem_instance_init(Object *obj)
+{
+ VirtIOMEM *vmem = VIRTIO_MEM(obj);
+
+ vmem->block_size = VIRTIO_MEM_MIN_BLOCK_SIZE;
+
+ object_property_add(obj, VIRTIO_MEM_SIZE_PROP, "size", virtio_mem_get_size,
+ NULL, NULL, NULL);
+ object_property_add(obj, VIRTIO_MEM_REQUESTED_SIZE_PROP, "size",
+ virtio_mem_get_requested_size,
+ virtio_mem_set_requested_size, NULL, NULL);
+ object_property_add(obj, VIRTIO_MEM_BLOCK_SIZE_PROP, "size",
+ virtio_mem_get_block_size, virtio_mem_set_block_size,
+ NULL, NULL);
+}
+
+static Property virtio_mem_properties[] = {
+ DEFINE_PROP_UINT64(VIRTIO_MEM_ADDR_PROP, VirtIOMEM, addr, 0),
+ DEFINE_PROP_UINT32(VIRTIO_MEM_NODE_PROP, VirtIOMEM, node, 0),
+ DEFINE_PROP_LINK(VIRTIO_MEM_MEMDEV_PROP, VirtIOMEM, memdev,
+ TYPE_MEMORY_BACKEND, HostMemoryBackend *),
+ DEFINE_PROP_END_OF_LIST(),
+};
+
+static void virtio_mem_class_init(ObjectClass *klass, void *data)
+{
+ DeviceClass *dc = DEVICE_CLASS(klass);
+ VirtioDeviceClass *vdc = VIRTIO_DEVICE_CLASS(klass);
+ VirtIOMEMClass *vmc = VIRTIO_MEM_CLASS(klass);
+
+ device_class_set_props(dc, virtio_mem_properties);
+ dc->vmsd = &vmstate_virtio_mem;
+
+ set_bit(DEVICE_CATEGORY_MISC, dc->categories);
+ vdc->realize = virtio_mem_device_realize;
+ vdc->unrealize = virtio_mem_device_unrealize;
+ vdc->get_config = virtio_mem_get_config;
+ vdc->get_features = virtio_mem_get_features;
+ vdc->vmsd = &vmstate_virtio_mem_device;
+
+ vmc->fill_device_info = virtio_mem_fill_device_info;
+ vmc->get_memory_region = virtio_mem_get_memory_region;
+}
+
+static const TypeInfo virtio_mem_info = {
+ .name = TYPE_VIRTIO_MEM,
+ .parent = TYPE_VIRTIO_DEVICE,
+ .instance_size = sizeof(VirtIOMEM),
+ .instance_init = virtio_mem_instance_init,
+ .class_init = virtio_mem_class_init,
+ .class_size = sizeof(VirtIOMEMClass),
+};
+
+static void virtio_register_types(void)
+{
+ type_register_static(&virtio_mem_info);
+}
+
+type_init(virtio_register_types)
diff --git a/include/hw/virtio/virtio-mem.h b/include/hw/virtio/virtio-mem.h
new file mode 100644
index 0000000000..6981096f7c
--- /dev/null
+++ b/include/hw/virtio/virtio-mem.h
@@ -0,0 +1,78 @@
+/*
+ * Virtio MEM device
+ *
+ * Copyright (C) 2020 Red Hat, Inc.
+ *
+ * Authors:
+ * David Hildenbrand <david@redhat.com>
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2.
+ * See the COPYING file in the top-level directory.
+ */
+
+#ifndef HW_VIRTIO_MEM_H
+#define HW_VIRTIO_MEM_H
+
+#include "standard-headers/linux/virtio_mem.h"
+#include "hw/virtio/virtio.h"
+#include "qapi/qapi-types-misc.h"
+#include "sysemu/hostmem.h"
+
+#define TYPE_VIRTIO_MEM "virtio-mem"
+
+#define VIRTIO_MEM(obj) \
+ OBJECT_CHECK(VirtIOMEM, (obj), TYPE_VIRTIO_MEM)
+#define VIRTIO_MEM_CLASS(oc) \
+ OBJECT_CLASS_CHECK(VirtIOMEMClass, (oc), TYPE_VIRTIO_MEM)
+#define VIRTIO_MEM_GET_CLASS(obj) \
+ OBJECT_GET_CLASS(VirtIOMEMClass, (obj), TYPE_VIRTIO_MEM)
+
+#define VIRTIO_MEM_MEMDEV_PROP "memdev"
+#define VIRTIO_MEM_NODE_PROP "node"
+#define VIRTIO_MEM_SIZE_PROP "size"
+#define VIRTIO_MEM_REQUESTED_SIZE_PROP "requested-size"
+#define VIRTIO_MEM_BLOCK_SIZE_PROP "block-size"
+#define VIRTIO_MEM_ADDR_PROP "memaddr"
+
+typedef struct VirtIOMEM {
+ VirtIODevice parent_obj;
+
+ /* guest -> host request queue */
+ VirtQueue *vq;
+
+ /* bitmap used to track unplugged memory */
+ int32_t bitmap_size;
+ unsigned long *bitmap;
+
+ /* assigned memory backend and memory region */
+ HostMemoryBackend *memdev;
+
+ /* NUMA node */
+ uint32_t node;
+
+ /* assigned address of the region in guest physical memory */
+ uint64_t addr;
+
+ /* usable region size (<= region_size) */
+ uint64_t usable_region_size;
+
+ /* actual size (how much the guest plugged) */
+ uint64_t size;
+
+ /* requested size */
+ uint64_t requested_size;
+
+ /* block size and alignment */
+ uint64_t block_size;
+} VirtIOMEM;
+
+typedef struct VirtIOMEMClass {
+ /* private */
+ VirtIODevice parent;
+
+ /* public */
+ void (*fill_device_info)(const VirtIOMEM *vmen, VirtioMEMDeviceInfo *vi);
+ MemoryRegion *(*get_memory_region)(VirtIOMEM *vmem, Error **errp);
+} VirtIOMEMClass;
+
+#endif
diff --git a/qapi/misc.json b/qapi/misc.json
index a5a0beb902..65ca3edf32 100644
--- a/qapi/misc.json
+++ b/qapi/misc.json
@@ -1356,19 +1356,56 @@
}
}
+##
+# @VirtioMEMDeviceInfo:
+#
+# VirtioMEMDevice state information
+#
+# @id: device's ID
+#
+# @memaddr: physical address in memory, where device is mapped
+#
+# @requested-size: the user requested size of the device
+#
+# @size: the (current) size of memory that the device provides
+#
+# @max-size: the maximum size of memory that the device can provide
+#
+# @block-size: the block size of memory that the device provides
+#
+# @node: NUMA node number where device is assigned to
+#
+# @memdev: memory backend linked with the region
+#
+# Since: 5.1
+##
+{ 'struct': 'VirtioMEMDeviceInfo',
+ 'data': { '*id': 'str',
+ 'memaddr': 'size',
+ 'requested-size': 'size',
+ 'size': 'size',
+ 'max-size': 'size',
+ 'block-size': 'size',
+ 'node': 'int',
+ 'memdev': 'str'
+ }
+}
+
##
# @MemoryDeviceInfo:
#
# Union containing information about a memory device
#
# nvdimm is included since 2.12. virtio-pmem is included since 4.1.
+# virtio-mem is included since 5.1.
#
# Since: 2.1
##
{ 'union': 'MemoryDeviceInfo',
'data': { 'dimm': 'PCDIMMDeviceInfo',
'nvdimm': 'PCDIMMDeviceInfo',
- 'virtio-pmem': 'VirtioPMEMDeviceInfo'
+ 'virtio-pmem': 'VirtioPMEMDeviceInfo',
+ 'virtio-mem': 'VirtioMEMDeviceInfo'
}
}
--
2.26.2
^ permalink raw reply related [flat|nested] 29+ messages in thread* Re: [PATCH v5 10/21] virtio-mem: Paravirtualized memory hot(un)plug
2020-06-26 7:22 ` [PATCH v5 10/21] virtio-mem: Paravirtualized memory hot(un)plug David Hildenbrand
@ 2020-06-30 10:06 ` Michael S. Tsirkin
2020-06-30 10:21 ` David Hildenbrand
0 siblings, 1 reply; 29+ messages in thread
From: Michael S. Tsirkin @ 2020-06-30 10:06 UTC (permalink / raw)
To: David Hildenbrand
Cc: qemu-devel, kvm, qemu-s390x, Richard Henderson, Paolo Bonzini,
Dr . David Alan Gilbert, Eduardo Habkost, Eric Blake,
Markus Armbruster, Igor Mammedov
On Fri, Jun 26, 2020 at 09:22:37AM +0200, David Hildenbrand wrote:
> This is the very basic/initial version of virtio-mem. An introduction to
> virtio-mem can be found in the Linux kernel driver [1]. While it can be
> used in the current state for hotplug of a smaller amount of memory, it
> will heavily benefit from resizeable memory regions in the future.
>
> Each virtio-mem device manages a memory region (provided via a memory
> backend). After requested by the hypervisor ("requested-size"), the
> guest can try to plug/unplug blocks of memory within that region, in order
> to reach the requested size. Initially, and after a reboot, all memory is
> unplugged (except in special cases - reboot during postcopy).
>
> The guest may only try to plug/unplug blocks of memory within the usable
> region size. The usable region size is a little bigger than the
> requested size, to give the device driver some flexibility. The usable
> region size will only grow, except on reboots or when all memory is
> requested to get unplugged. The guest can never plug more memory than
> requested. Unplugged memory will get zapped/discarded, similar to in a
> balloon device.
>
> The block size is variable, however, it is always chosen in a way such that
> THP splits are avoided (e.g., 2MB). The state of each block
> (plugged/unplugged) is tracked in a bitmap.
>
> As virtio-mem devices (e.g., virtio-mem-pci) will be memory devices, we now
> expose "VirtioMEMDeviceInfo" via "query-memory-devices".
>
> --------------------------------------------------------------------------
>
> There are two important follow-up items that are in the works:
> 1. Resizeable memory regions: Use resizeable allocations/RAM blocks to
> grow/shrink along with the usable region size. This avoids creating
> initially very big VMAs, RAM blocks, and KVM slots.
> 2. Protection of unplugged memory: Make sure the gust cannot actually
> make use of unplugged memory.
>
> Other follow-up items that are in the works:
> 1. Exclude unplugged memory during migration (via precopy notifier).
> 2. Handle remapping of memory.
> 3. Support for other architectures.
Question: I see that this does not check qemu_balloon_is_inhibited -
is that because this works with VFIO, somehow?
Or is this an oversight?
Thanks!
> --------------------------------------------------------------------------
>
> Example usage (virtio-mem-pci is introduced in follow-up patches):
>
> Start QEMU with two virtio-mem devices (one per NUMA node):
> $ qemu-system-x86_64 -m 4G,maxmem=20G \
> -smp sockets=2,cores=2 \
> -numa node,nodeid=0,cpus=0-1 -numa node,nodeid=1,cpus=2-3 \
> [...]
> -object memory-backend-ram,id=mem0,size=8G \
> -device virtio-mem-pci,id=vm0,memdev=mem0,node=0,requested-size=0M \
> -object memory-backend-ram,id=mem1,size=8G \
> -device virtio-mem-pci,id=vm1,memdev=mem1,node=1,requested-size=1G
>
> Query the configuration:
> (qemu) info memory-devices
> Memory device [virtio-mem]: "vm0"
> memaddr: 0x140000000
> node: 0
> requested-size: 0
> size: 0
> max-size: 8589934592
> block-size: 2097152
> memdev: /objects/mem0
> Memory device [virtio-mem]: "vm1"
> memaddr: 0x340000000
> node: 1
> requested-size: 1073741824
> size: 1073741824
> max-size: 8589934592
> block-size: 2097152
> memdev: /objects/mem1
>
> Add some memory to node 0:
> (qemu) qom-set vm0 requested-size 500M
>
> Remove some memory from node 1:
> (qemu) qom-set vm1 requested-size 200M
>
> Query the configuration again:
> (qemu) info memory-devices
> Memory device [virtio-mem]: "vm0"
> memaddr: 0x140000000
> node: 0
> requested-size: 524288000
> size: 524288000
> max-size: 8589934592
> block-size: 2097152
> memdev: /objects/mem0
> Memory device [virtio-mem]: "vm1"
> memaddr: 0x340000000
> node: 1
> requested-size: 209715200
> size: 209715200
> max-size: 8589934592
> block-size: 2097152
> memdev: /objects/mem1
>
> [1] https://lkml.kernel.org/r/20200311171422.10484-1-david@redhat.com
>
> Cc: "Michael S. Tsirkin" <mst@redhat.com>
> Cc: Eric Blake <eblake@redhat.com>
> Cc: Markus Armbruster <armbru@redhat.com>
> Cc: "Dr. David Alan Gilbert" <dgilbert@redhat.com>
> Cc: Igor Mammedov <imammedo@redhat.com>
> Signed-off-by: David Hildenbrand <david@redhat.com>
> ---
> hw/virtio/Kconfig | 11 +
> hw/virtio/Makefile.objs | 1 +
> hw/virtio/virtio-mem.c | 724 +++++++++++++++++++++++++++++++++
> include/hw/virtio/virtio-mem.h | 78 ++++
> qapi/misc.json | 39 +-
> 5 files changed, 852 insertions(+), 1 deletion(-)
> create mode 100644 hw/virtio/virtio-mem.c
> create mode 100644 include/hw/virtio/virtio-mem.h
>
> diff --git a/hw/virtio/Kconfig b/hw/virtio/Kconfig
> index 83122424fa..0eda25c4e1 100644
> --- a/hw/virtio/Kconfig
> +++ b/hw/virtio/Kconfig
> @@ -47,3 +47,14 @@ config VIRTIO_PMEM
> depends on VIRTIO
> depends on VIRTIO_PMEM_SUPPORTED
> select MEM_DEVICE
> +
> +config VIRTIO_MEM_SUPPORTED
> + bool
> +
> +config VIRTIO_MEM
> + bool
> + default y
> + depends on VIRTIO
> + depends on LINUX
> + depends on VIRTIO_MEM_SUPPORTED
> + select MEM_DEVICE
> diff --git a/hw/virtio/Makefile.objs b/hw/virtio/Makefile.objs
> index 13e75f171f..f3a65e01b7 100644
> --- a/hw/virtio/Makefile.objs
> +++ b/hw/virtio/Makefile.objs
> @@ -19,6 +19,7 @@ obj-$(call land,$(CONFIG_VHOST_USER_FS),$(CONFIG_VIRTIO_PCI)) += vhost-user-fs-p
> obj-$(CONFIG_VIRTIO_IOMMU) += virtio-iommu.o
> obj-$(CONFIG_VHOST_VSOCK) += vhost-vsock-common.o vhost-vsock.o
> obj-$(CONFIG_VHOST_USER_VSOCK) += vhost-vsock-common.o vhost-user-vsock.o
> +obj-$(CONFIG_VIRTIO_MEM) += virtio-mem.o
>
> ifeq ($(CONFIG_VIRTIO_PCI),y)
> obj-$(CONFIG_VHOST_VSOCK) += vhost-vsock-pci.o
> diff --git a/hw/virtio/virtio-mem.c b/hw/virtio/virtio-mem.c
> new file mode 100644
> index 0000000000..d8a0c974d3
> --- /dev/null
> +++ b/hw/virtio/virtio-mem.c
> @@ -0,0 +1,724 @@
> +/*
> + * Virtio MEM device
> + *
> + * Copyright (C) 2020 Red Hat, Inc.
> + *
> + * Authors:
> + * David Hildenbrand <david@redhat.com>
> + *
> + * This work is licensed under the terms of the GNU GPL, version 2.
> + * See the COPYING file in the top-level directory.
> + */
> +
> +#include "qemu/osdep.h"
> +#include "qemu-common.h"
> +#include "qemu/iov.h"
> +#include "qemu/cutils.h"
> +#include "qemu/error-report.h"
> +#include "qemu/units.h"
> +#include "sysemu/numa.h"
> +#include "sysemu/sysemu.h"
> +#include "sysemu/reset.h"
> +#include "hw/virtio/virtio.h"
> +#include "hw/virtio/virtio-bus.h"
> +#include "hw/virtio/virtio-access.h"
> +#include "hw/virtio/virtio-mem.h"
> +#include "qapi/error.h"
> +#include "qapi/visitor.h"
> +#include "exec/ram_addr.h"
> +#include "migration/misc.h"
> +#include "hw/boards.h"
> +#include "hw/qdev-properties.h"
> +#include "config-devices.h"
> +
> +/*
> + * Use QEMU_VMALLOC_ALIGN, so no THP will have to be split when unplugging
> + * memory (e.g., 2MB on x86_64).
> + */
> +#define VIRTIO_MEM_MIN_BLOCK_SIZE QEMU_VMALLOC_ALIGN
> +/*
> + * Size the usable region bigger than the requested size if possible. Esp.
> + * Linux guests will only add (aligned) memory blocks in case they fully
> + * fit into the usable region, but plug+online only a subset of the pages.
> + * The memory block size corresponds mostly to the section size.
> + *
> + * This allows e.g., to add 20MB with a section size of 128MB on x86_64, and
> + * a section size of 1GB on arm64 (as long as the start address is properly
> + * aligned, similar to ordinary DIMMs).
> + *
> + * We can change this at any time and maybe even make it configurable if
> + * necessary (as the section size can change). But it's more likely that the
> + * section size will rather get smaller and not bigger over time.
> + */
> +#if defined(__x86_64__)
> +#define VIRTIO_MEM_USABLE_EXTENT (2 * (128 * MiB))
> +#else
> +#error VIRTIO_MEM_USABLE_EXTENT not defined
> +#endif
> +
> +static bool virtio_mem_is_busy(void)
> +{
> + /*
> + * Postcopy cannot handle concurrent discards and we don't want to migrate
> + * pages on-demand with stale content when plugging new blocks.
> + */
> + return migration_in_incoming_postcopy();
> +}
> +
> +static bool virtio_mem_test_bitmap(VirtIOMEM *vmem, uint64_t start_gpa,
> + uint64_t size, bool plugged)
> +{
> + const unsigned long first_bit = (start_gpa - vmem->addr) / vmem->block_size;
> + const unsigned long last_bit = first_bit + (size / vmem->block_size) - 1;
> + unsigned long found_bit;
> +
> + /* We fake a shorter bitmap to avoid searching too far. */
> + if (plugged) {
> + found_bit = find_next_zero_bit(vmem->bitmap, last_bit + 1, first_bit);
> + } else {
> + found_bit = find_next_bit(vmem->bitmap, last_bit + 1, first_bit);
> + }
> + return found_bit > last_bit;
> +}
> +
> +static void virtio_mem_set_bitmap(VirtIOMEM *vmem, uint64_t start_gpa,
> + uint64_t size, bool plugged)
> +{
> + const unsigned long bit = (start_gpa - vmem->addr) / vmem->block_size;
> + const unsigned long nbits = size / vmem->block_size;
> +
> + if (plugged) {
> + bitmap_set(vmem->bitmap, bit, nbits);
> + } else {
> + bitmap_clear(vmem->bitmap, bit, nbits);
> + }
> +}
> +
> +static void virtio_mem_send_response(VirtIOMEM *vmem, VirtQueueElement *elem,
> + struct virtio_mem_resp *resp)
> +{
> + VirtIODevice *vdev = VIRTIO_DEVICE(vmem);
> + VirtQueue *vq = vmem->vq;
> +
> + iov_from_buf(elem->in_sg, elem->in_num, 0, resp, sizeof(*resp));
> +
> + virtqueue_push(vq, elem, sizeof(*resp));
> + virtio_notify(vdev, vq);
> +}
> +
> +static void virtio_mem_send_response_simple(VirtIOMEM *vmem,
> + VirtQueueElement *elem,
> + uint16_t type)
> +{
> + struct virtio_mem_resp resp = {
> + .type = cpu_to_le16(type),
> + };
> +
> + virtio_mem_send_response(vmem, elem, &resp);
> +}
> +
> +static bool virtio_mem_valid_range(VirtIOMEM *vmem, uint64_t gpa, uint64_t size)
> +{
> + if (!QEMU_IS_ALIGNED(gpa, vmem->block_size)) {
> + return false;
> + }
> + if (gpa + size < gpa || !size) {
> + return false;
> + }
> + if (gpa < vmem->addr || gpa >= vmem->addr + vmem->usable_region_size) {
> + return false;
> + }
> + if (gpa + size > vmem->addr + vmem->usable_region_size) {
> + return false;
> + }
> + return true;
> +}
> +
> +static int virtio_mem_set_block_state(VirtIOMEM *vmem, uint64_t start_gpa,
> + uint64_t size, bool plug)
> +{
> + const uint64_t offset = start_gpa - vmem->addr;
> + int ret;
> +
> + if (virtio_mem_is_busy()) {
> + return -EBUSY;
> + }
> +
> + if (!plug) {
> + ret = ram_block_discard_range(vmem->memdev->mr.ram_block, offset, size);
> + if (ret) {
> + error_report("Unexpected error discarding RAM: %s",
> + strerror(-ret));
> + return -EBUSY;
> + }
> + }
> + virtio_mem_set_bitmap(vmem, start_gpa, size, plug);
> + return 0;
> +}
> +
> +static int virtio_mem_state_change_request(VirtIOMEM *vmem, uint64_t gpa,
> + uint16_t nb_blocks, bool plug)
> +{
> + const uint64_t size = nb_blocks * vmem->block_size;
> + int ret;
> +
> + if (!virtio_mem_valid_range(vmem, gpa, size)) {
> + return VIRTIO_MEM_RESP_ERROR;
> + }
> +
> + if (plug && (vmem->size + size > vmem->requested_size)) {
> + return VIRTIO_MEM_RESP_NACK;
> + }
> +
> + /* test if really all blocks are in the opposite state */
> + if (!virtio_mem_test_bitmap(vmem, gpa, size, !plug)) {
> + return VIRTIO_MEM_RESP_ERROR;
> + }
> +
> + ret = virtio_mem_set_block_state(vmem, gpa, size, plug);
> + if (ret) {
> + return VIRTIO_MEM_RESP_BUSY;
> + }
> + if (plug) {
> + vmem->size += size;
> + } else {
> + vmem->size -= size;
> + }
> + return VIRTIO_MEM_RESP_ACK;
> +}
> +
> +static void virtio_mem_plug_request(VirtIOMEM *vmem, VirtQueueElement *elem,
> + struct virtio_mem_req *req)
> +{
> + const uint64_t gpa = le64_to_cpu(req->u.plug.addr);
> + const uint16_t nb_blocks = le16_to_cpu(req->u.plug.nb_blocks);
> + uint16_t type;
> +
> + type = virtio_mem_state_change_request(vmem, gpa, nb_blocks, true);
> + virtio_mem_send_response_simple(vmem, elem, type);
> +}
> +
> +static void virtio_mem_unplug_request(VirtIOMEM *vmem, VirtQueueElement *elem,
> + struct virtio_mem_req *req)
> +{
> + const uint64_t gpa = le64_to_cpu(req->u.unplug.addr);
> + const uint16_t nb_blocks = le16_to_cpu(req->u.unplug.nb_blocks);
> + uint16_t type;
> +
> + type = virtio_mem_state_change_request(vmem, gpa, nb_blocks, false);
> + virtio_mem_send_response_simple(vmem, elem, type);
> +}
> +
> +static void virtio_mem_resize_usable_region(VirtIOMEM *vmem,
> + uint64_t requested_size,
> + bool can_shrink)
> +{
> + uint64_t newsize = MIN(memory_region_size(&vmem->memdev->mr),
> + requested_size + VIRTIO_MEM_USABLE_EXTENT);
> +
> + if (!requested_size) {
> + newsize = 0;
> + }
> +
> + if (newsize < vmem->usable_region_size && !can_shrink) {
> + return;
> + }
> +
> + vmem->usable_region_size = newsize;
> +}
> +
> +static int virtio_mem_unplug_all(VirtIOMEM *vmem)
> +{
> + RAMBlock *rb = vmem->memdev->mr.ram_block;
> + int ret;
> +
> + if (virtio_mem_is_busy()) {
> + return -EBUSY;
> + }
> +
> + ret = ram_block_discard_range(rb, 0, qemu_ram_get_used_length(rb));
> + if (ret) {
> + error_report("Unexpected error discarding RAM: %s", strerror(-ret));
> + return -EBUSY;
> + }
> + bitmap_clear(vmem->bitmap, 0, vmem->bitmap_size);
> + vmem->size = 0;
> +
> + virtio_mem_resize_usable_region(vmem, vmem->requested_size, true);
> + return 0;
> +}
> +
> +static void virtio_mem_unplug_all_request(VirtIOMEM *vmem,
> + VirtQueueElement *elem)
> +{
> + if (virtio_mem_unplug_all(vmem)) {
> + virtio_mem_send_response_simple(vmem, elem, VIRTIO_MEM_RESP_BUSY);
> + } else {
> + virtio_mem_send_response_simple(vmem, elem, VIRTIO_MEM_RESP_ACK);
> + }
> +}
> +
> +static void virtio_mem_state_request(VirtIOMEM *vmem, VirtQueueElement *elem,
> + struct virtio_mem_req *req)
> +{
> + const uint16_t nb_blocks = le16_to_cpu(req->u.state.nb_blocks);
> + const uint64_t gpa = le64_to_cpu(req->u.state.addr);
> + const uint64_t size = nb_blocks * vmem->block_size;
> + struct virtio_mem_resp resp = {
> + .type = cpu_to_le16(VIRTIO_MEM_RESP_ACK),
> + };
> +
> + if (!virtio_mem_valid_range(vmem, gpa, size)) {
> + virtio_mem_send_response_simple(vmem, elem, VIRTIO_MEM_RESP_ERROR);
> + return;
> + }
> +
> + if (virtio_mem_test_bitmap(vmem, gpa, size, true)) {
> + resp.u.state.state = cpu_to_le16(VIRTIO_MEM_STATE_PLUGGED);
> + } else if (virtio_mem_test_bitmap(vmem, gpa, size, false)) {
> + resp.u.state.state = cpu_to_le16(VIRTIO_MEM_STATE_UNPLUGGED);
> + } else {
> + resp.u.state.state = cpu_to_le16(VIRTIO_MEM_STATE_MIXED);
> + }
> + virtio_mem_send_response(vmem, elem, &resp);
> +}
> +
> +static void virtio_mem_handle_request(VirtIODevice *vdev, VirtQueue *vq)
> +{
> + const int len = sizeof(struct virtio_mem_req);
> + VirtIOMEM *vmem = VIRTIO_MEM(vdev);
> + VirtQueueElement *elem;
> + struct virtio_mem_req req;
> + uint16_t type;
> +
> + while (true) {
> + elem = virtqueue_pop(vq, sizeof(VirtQueueElement));
> + if (!elem) {
> + return;
> + }
> +
> + if (iov_to_buf(elem->out_sg, elem->out_num, 0, &req, len) < len) {
> + virtio_error(vdev, "virtio-mem protocol violation: invalid request"
> + " size: %d", len);
> + g_free(elem);
> + return;
> + }
> +
> + if (iov_size(elem->in_sg, elem->in_num) <
> + sizeof(struct virtio_mem_resp)) {
> + virtio_error(vdev, "virtio-mem protocol violation: not enough space"
> + " for response: %zu",
> + iov_size(elem->in_sg, elem->in_num));
> + g_free(elem);
> + return;
> + }
> +
> + type = le16_to_cpu(req.type);
> + switch (type) {
> + case VIRTIO_MEM_REQ_PLUG:
> + virtio_mem_plug_request(vmem, elem, &req);
> + break;
> + case VIRTIO_MEM_REQ_UNPLUG:
> + virtio_mem_unplug_request(vmem, elem, &req);
> + break;
> + case VIRTIO_MEM_REQ_UNPLUG_ALL:
> + virtio_mem_unplug_all_request(vmem, elem);
> + break;
> + case VIRTIO_MEM_REQ_STATE:
> + virtio_mem_state_request(vmem, elem, &req);
> + break;
> + default:
> + virtio_error(vdev, "virtio-mem protocol violation: unknown request"
> + " type: %d", type);
> + g_free(elem);
> + return;
> + }
> +
> + g_free(elem);
> + }
> +}
> +
> +static void virtio_mem_get_config(VirtIODevice *vdev, uint8_t *config_data)
> +{
> + VirtIOMEM *vmem = VIRTIO_MEM(vdev);
> + struct virtio_mem_config *config = (void *) config_data;
> +
> + config->block_size = cpu_to_le64(vmem->block_size);
> + config->node_id = cpu_to_le16(vmem->node);
> + config->requested_size = cpu_to_le64(vmem->requested_size);
> + config->plugged_size = cpu_to_le64(vmem->size);
> + config->addr = cpu_to_le64(vmem->addr);
> + config->region_size = cpu_to_le64(memory_region_size(&vmem->memdev->mr));
> + config->usable_region_size = cpu_to_le64(vmem->usable_region_size);
> +}
> +
> +static uint64_t virtio_mem_get_features(VirtIODevice *vdev, uint64_t features,
> + Error **errp)
> +{
> + MachineState *ms = MACHINE(qdev_get_machine());
> +
> + if (ms->numa_state) {
> +#if defined(CONFIG_ACPI)
> + virtio_add_feature(&features, VIRTIO_MEM_F_ACPI_PXM);
> +#endif
> + }
> + return features;
> +}
> +
> +static void virtio_mem_system_reset(void *opaque)
> +{
> + VirtIOMEM *vmem = VIRTIO_MEM(opaque);
> +
> + /*
> + * During usual resets, we will unplug all memory and shrink the usable
> + * region size. This is, however, not possible in all scenarios. Then,
> + * the guest has to deal with this manually (VIRTIO_MEM_REQ_UNPLUG_ALL).
> + */
> + virtio_mem_unplug_all(vmem);
> +}
> +
> +static void virtio_mem_device_realize(DeviceState *dev, Error **errp)
> +{
> + MachineState *ms = MACHINE(qdev_get_machine());
> + int nb_numa_nodes = ms->numa_state ? ms->numa_state->num_nodes : 0;
> + VirtIODevice *vdev = VIRTIO_DEVICE(dev);
> + VirtIOMEM *vmem = VIRTIO_MEM(dev);
> + uint64_t page_size;
> + RAMBlock *rb;
> + int ret;
> +
> + if (!vmem->memdev) {
> + error_setg(errp, "'%s' property is not set", VIRTIO_MEM_MEMDEV_PROP);
> + return;
> + } else if (host_memory_backend_is_mapped(vmem->memdev)) {
> + char *path = object_get_canonical_path_component(OBJECT(vmem->memdev));
> +
> + error_setg(errp, "'%s' property specifies a busy memdev: %s",
> + VIRTIO_MEM_MEMDEV_PROP, path);
> + g_free(path);
> + return;
> + } else if (!memory_region_is_ram(&vmem->memdev->mr) ||
> + memory_region_is_rom(&vmem->memdev->mr) ||
> + !vmem->memdev->mr.ram_block) {
> + error_setg(errp, "'%s' property specifies an unsupported memdev",
> + VIRTIO_MEM_MEMDEV_PROP);
> + return;
> + }
> +
> + if ((nb_numa_nodes && vmem->node >= nb_numa_nodes) ||
> + (!nb_numa_nodes && vmem->node)) {
> + error_setg(errp, "'%s' property has value '%" PRIu32 "', which exceeds"
> + "the number of numa nodes: %d", VIRTIO_MEM_NODE_PROP,
> + vmem->node, nb_numa_nodes ? nb_numa_nodes : 1);
> + return;
> + }
> +
> + if (enable_mlock) {
> + error_setg(errp, "Incompatible with mlock");
> + return;
> + }
> +
> + rb = vmem->memdev->mr.ram_block;
> + page_size = qemu_ram_pagesize(rb);
> +
> + if (vmem->block_size < page_size) {
> + error_setg(errp, "'%s' property has to be at least the page size (0x%"
> + PRIx64 ")", VIRTIO_MEM_BLOCK_SIZE_PROP, page_size);
> + return;
> + } else if (!QEMU_IS_ALIGNED(vmem->requested_size, vmem->block_size)) {
> + error_setg(errp, "'%s' property has to be multiples of '%s' (0x%" PRIx64
> + ")", VIRTIO_MEM_REQUESTED_SIZE_PROP,
> + VIRTIO_MEM_BLOCK_SIZE_PROP, vmem->block_size);
> + return;
> + } else if (!QEMU_IS_ALIGNED(memory_region_size(&vmem->memdev->mr),
> + vmem->block_size)) {
> + error_setg(errp, "'%s' property memdev size has to be multiples of"
> + "'%s' (0x%" PRIx64 ")", VIRTIO_MEM_MEMDEV_PROP,
> + VIRTIO_MEM_BLOCK_SIZE_PROP, vmem->block_size);
> + return;
> + }
> +
> + if (ram_block_discard_require(true)) {
> + error_setg(errp, "Discarding RAM is disabled");
> + return;
> + }
> +
> + ret = ram_block_discard_range(rb, 0, qemu_ram_get_used_length(rb));
> + if (ret) {
> + error_setg_errno(errp, -ret, "Unexpected error discarding RAM");
> + ram_block_discard_require(false);
> + return;
> + }
> +
> + virtio_mem_resize_usable_region(vmem, vmem->requested_size, true);
> +
> + vmem->bitmap_size = memory_region_size(&vmem->memdev->mr) /
> + vmem->block_size;
> + vmem->bitmap = bitmap_new(vmem->bitmap_size);
> +
> + virtio_init(vdev, TYPE_VIRTIO_MEM, VIRTIO_ID_MEM,
> + sizeof(struct virtio_mem_config));
> + vmem->vq = virtio_add_queue(vdev, 128, virtio_mem_handle_request);
> +
> + host_memory_backend_set_mapped(vmem->memdev, true);
> + vmstate_register_ram(&vmem->memdev->mr, DEVICE(vmem));
> + qemu_register_reset(virtio_mem_system_reset, vmem);
> +}
> +
> +static void virtio_mem_device_unrealize(DeviceState *dev)
> +{
> + VirtIODevice *vdev = VIRTIO_DEVICE(dev);
> + VirtIOMEM *vmem = VIRTIO_MEM(dev);
> +
> + qemu_unregister_reset(virtio_mem_system_reset, vmem);
> + vmstate_unregister_ram(&vmem->memdev->mr, DEVICE(vmem));
> + host_memory_backend_set_mapped(vmem->memdev, false);
> + virtio_del_queue(vdev, 0);
> + virtio_cleanup(vdev);
> + g_free(vmem->bitmap);
> + ram_block_discard_require(false);
> +}
> +
> +static int virtio_mem_restore_unplugged(VirtIOMEM *vmem)
> +{
> + RAMBlock *rb = vmem->memdev->mr.ram_block;
> + unsigned long first_zero_bit, last_zero_bit;
> + uint64_t offset, length;
> + int ret;
> +
> + /* Find consecutive unplugged blocks and discard the consecutive range. */
> + first_zero_bit = find_first_zero_bit(vmem->bitmap, vmem->bitmap_size);
> + while (first_zero_bit < vmem->bitmap_size) {
> + offset = first_zero_bit * vmem->block_size;
> + last_zero_bit = find_next_bit(vmem->bitmap, vmem->bitmap_size,
> + first_zero_bit + 1) - 1;
> + length = (last_zero_bit - first_zero_bit + 1) * vmem->block_size;
> +
> + ret = ram_block_discard_range(rb, offset, length);
> + if (ret) {
> + error_report("Unexpected error discarding RAM: %s",
> + strerror(-ret));
> + return -EINVAL;
> + }
> + first_zero_bit = find_next_zero_bit(vmem->bitmap, vmem->bitmap_size,
> + last_zero_bit + 2);
> + }
> + return 0;
> +}
> +
> +static int virtio_mem_post_load(void *opaque, int version_id)
> +{
> + if (migration_in_incoming_postcopy()) {
> + return 0;
> + }
> +
> + return virtio_mem_restore_unplugged(VIRTIO_MEM(opaque));
> +}
> +
> +static const VMStateDescription vmstate_virtio_mem_device = {
> + .name = "virtio-mem-device",
> + .minimum_version_id = 1,
> + .version_id = 1,
> + .post_load = virtio_mem_post_load,
> + .fields = (VMStateField[]) {
> + VMSTATE_UINT64(usable_region_size, VirtIOMEM),
> + VMSTATE_UINT64(size, VirtIOMEM),
> + VMSTATE_UINT64(requested_size, VirtIOMEM),
> + VMSTATE_BITMAP(bitmap, VirtIOMEM, 0, bitmap_size),
> + VMSTATE_END_OF_LIST()
> + },
> +};
> +
> +static const VMStateDescription vmstate_virtio_mem = {
> + .name = "virtio-mem",
> + .minimum_version_id = 1,
> + .version_id = 1,
> + .fields = (VMStateField[]) {
> + VMSTATE_VIRTIO_DEVICE,
> + VMSTATE_END_OF_LIST()
> + },
> +};
> +
> +static void virtio_mem_fill_device_info(const VirtIOMEM *vmem,
> + VirtioMEMDeviceInfo *vi)
> +{
> + vi->memaddr = vmem->addr;
> + vi->node = vmem->node;
> + vi->requested_size = vmem->requested_size;
> + vi->size = vmem->size;
> + vi->max_size = memory_region_size(&vmem->memdev->mr);
> + vi->block_size = vmem->block_size;
> + vi->memdev = object_get_canonical_path(OBJECT(vmem->memdev));
> +}
> +
> +static MemoryRegion *virtio_mem_get_memory_region(VirtIOMEM *vmem, Error **errp)
> +{
> + if (!vmem->memdev) {
> + error_setg(errp, "'%s' property must be set", VIRTIO_MEM_MEMDEV_PROP);
> + return NULL;
> + }
> +
> + return &vmem->memdev->mr;
> +}
> +
> +static void virtio_mem_get_size(Object *obj, Visitor *v, const char *name,
> + void *opaque, Error **errp)
> +{
> + const VirtIOMEM *vmem = VIRTIO_MEM(obj);
> + uint64_t value = vmem->size;
> +
> + visit_type_size(v, name, &value, errp);
> +}
> +
> +static void virtio_mem_get_requested_size(Object *obj, Visitor *v,
> + const char *name, void *opaque,
> + Error **errp)
> +{
> + const VirtIOMEM *vmem = VIRTIO_MEM(obj);
> + uint64_t value = vmem->requested_size;
> +
> + visit_type_size(v, name, &value, errp);
> +}
> +
> +static void virtio_mem_set_requested_size(Object *obj, Visitor *v,
> + const char *name, void *opaque,
> + Error **errp)
> +{
> + VirtIOMEM *vmem = VIRTIO_MEM(obj);
> + Error *err = NULL;
> + uint64_t value;
> +
> + visit_type_size(v, name, &value, &err);
> + if (err) {
> + error_propagate(errp, err);
> + return;
> + }
> +
> + /*
> + * The block size and memory backend are not fixed until the device was
> + * realized. realize() will verify these properties then.
> + */
> + if (DEVICE(obj)->realized) {
> + if (!QEMU_IS_ALIGNED(value, vmem->block_size)) {
> + error_setg(errp, "'%s' has to be multiples of '%s' (0x%" PRIx64
> + ")", name, VIRTIO_MEM_BLOCK_SIZE_PROP,
> + vmem->block_size);
> + return;
> + } else if (value > memory_region_size(&vmem->memdev->mr)) {
> + error_setg(errp, "'%s' cannot exceed the memory backend size"
> + "(0x%" PRIx64 ")", name,
> + memory_region_size(&vmem->memdev->mr));
> + return;
> + }
> +
> + if (value != vmem->requested_size) {
> + virtio_mem_resize_usable_region(vmem, value, false);
> + vmem->requested_size = value;
> + }
> + /*
> + * Trigger a config update so the guest gets notified. We trigger
> + * even if the size didn't change (especially helpful for debugging).
> + */
> + virtio_notify_config(VIRTIO_DEVICE(vmem));
> + } else {
> + vmem->requested_size = value;
> + }
> +}
> +
> +static void virtio_mem_get_block_size(Object *obj, Visitor *v, const char *name,
> + void *opaque, Error **errp)
> +{
> + const VirtIOMEM *vmem = VIRTIO_MEM(obj);
> + uint64_t value = vmem->block_size;
> +
> + visit_type_size(v, name, &value, errp);
> +}
> +
> +static void virtio_mem_set_block_size(Object *obj, Visitor *v, const char *name,
> + void *opaque, Error **errp)
> +{
> + VirtIOMEM *vmem = VIRTIO_MEM(obj);
> + Error *err = NULL;
> + uint64_t value;
> +
> + if (DEVICE(obj)->realized) {
> + error_setg(errp, "'%s' cannot be changed", name);
> + return;
> + }
> +
> + visit_type_size(v, name, &value, &err);
> + if (err) {
> + error_propagate(errp, err);
> + return;
> + }
> +
> + if (value < VIRTIO_MEM_MIN_BLOCK_SIZE) {
> + error_setg(errp, "'%s' property has to be at least 0x%" PRIx32, name,
> + VIRTIO_MEM_MIN_BLOCK_SIZE);
> + return;
> + } else if (!is_power_of_2(value)) {
> + error_setg(errp, "'%s' property has to be a power of two", name);
> + return;
> + }
> + vmem->block_size = value;
> +}
> +
> +static void virtio_mem_instance_init(Object *obj)
> +{
> + VirtIOMEM *vmem = VIRTIO_MEM(obj);
> +
> + vmem->block_size = VIRTIO_MEM_MIN_BLOCK_SIZE;
> +
> + object_property_add(obj, VIRTIO_MEM_SIZE_PROP, "size", virtio_mem_get_size,
> + NULL, NULL, NULL);
> + object_property_add(obj, VIRTIO_MEM_REQUESTED_SIZE_PROP, "size",
> + virtio_mem_get_requested_size,
> + virtio_mem_set_requested_size, NULL, NULL);
> + object_property_add(obj, VIRTIO_MEM_BLOCK_SIZE_PROP, "size",
> + virtio_mem_get_block_size, virtio_mem_set_block_size,
> + NULL, NULL);
> +}
> +
> +static Property virtio_mem_properties[] = {
> + DEFINE_PROP_UINT64(VIRTIO_MEM_ADDR_PROP, VirtIOMEM, addr, 0),
> + DEFINE_PROP_UINT32(VIRTIO_MEM_NODE_PROP, VirtIOMEM, node, 0),
> + DEFINE_PROP_LINK(VIRTIO_MEM_MEMDEV_PROP, VirtIOMEM, memdev,
> + TYPE_MEMORY_BACKEND, HostMemoryBackend *),
> + DEFINE_PROP_END_OF_LIST(),
> +};
> +
> +static void virtio_mem_class_init(ObjectClass *klass, void *data)
> +{
> + DeviceClass *dc = DEVICE_CLASS(klass);
> + VirtioDeviceClass *vdc = VIRTIO_DEVICE_CLASS(klass);
> + VirtIOMEMClass *vmc = VIRTIO_MEM_CLASS(klass);
> +
> + device_class_set_props(dc, virtio_mem_properties);
> + dc->vmsd = &vmstate_virtio_mem;
> +
> + set_bit(DEVICE_CATEGORY_MISC, dc->categories);
> + vdc->realize = virtio_mem_device_realize;
> + vdc->unrealize = virtio_mem_device_unrealize;
> + vdc->get_config = virtio_mem_get_config;
> + vdc->get_features = virtio_mem_get_features;
> + vdc->vmsd = &vmstate_virtio_mem_device;
> +
> + vmc->fill_device_info = virtio_mem_fill_device_info;
> + vmc->get_memory_region = virtio_mem_get_memory_region;
> +}
> +
> +static const TypeInfo virtio_mem_info = {
> + .name = TYPE_VIRTIO_MEM,
> + .parent = TYPE_VIRTIO_DEVICE,
> + .instance_size = sizeof(VirtIOMEM),
> + .instance_init = virtio_mem_instance_init,
> + .class_init = virtio_mem_class_init,
> + .class_size = sizeof(VirtIOMEMClass),
> +};
> +
> +static void virtio_register_types(void)
> +{
> + type_register_static(&virtio_mem_info);
> +}
> +
> +type_init(virtio_register_types)
> diff --git a/include/hw/virtio/virtio-mem.h b/include/hw/virtio/virtio-mem.h
> new file mode 100644
> index 0000000000..6981096f7c
> --- /dev/null
> +++ b/include/hw/virtio/virtio-mem.h
> @@ -0,0 +1,78 @@
> +/*
> + * Virtio MEM device
> + *
> + * Copyright (C) 2020 Red Hat, Inc.
> + *
> + * Authors:
> + * David Hildenbrand <david@redhat.com>
> + *
> + * This work is licensed under the terms of the GNU GPL, version 2.
> + * See the COPYING file in the top-level directory.
> + */
> +
> +#ifndef HW_VIRTIO_MEM_H
> +#define HW_VIRTIO_MEM_H
> +
> +#include "standard-headers/linux/virtio_mem.h"
> +#include "hw/virtio/virtio.h"
> +#include "qapi/qapi-types-misc.h"
> +#include "sysemu/hostmem.h"
> +
> +#define TYPE_VIRTIO_MEM "virtio-mem"
> +
> +#define VIRTIO_MEM(obj) \
> + OBJECT_CHECK(VirtIOMEM, (obj), TYPE_VIRTIO_MEM)
> +#define VIRTIO_MEM_CLASS(oc) \
> + OBJECT_CLASS_CHECK(VirtIOMEMClass, (oc), TYPE_VIRTIO_MEM)
> +#define VIRTIO_MEM_GET_CLASS(obj) \
> + OBJECT_GET_CLASS(VirtIOMEMClass, (obj), TYPE_VIRTIO_MEM)
> +
> +#define VIRTIO_MEM_MEMDEV_PROP "memdev"
> +#define VIRTIO_MEM_NODE_PROP "node"
> +#define VIRTIO_MEM_SIZE_PROP "size"
> +#define VIRTIO_MEM_REQUESTED_SIZE_PROP "requested-size"
> +#define VIRTIO_MEM_BLOCK_SIZE_PROP "block-size"
> +#define VIRTIO_MEM_ADDR_PROP "memaddr"
> +
> +typedef struct VirtIOMEM {
> + VirtIODevice parent_obj;
> +
> + /* guest -> host request queue */
> + VirtQueue *vq;
> +
> + /* bitmap used to track unplugged memory */
> + int32_t bitmap_size;
> + unsigned long *bitmap;
> +
> + /* assigned memory backend and memory region */
> + HostMemoryBackend *memdev;
> +
> + /* NUMA node */
> + uint32_t node;
> +
> + /* assigned address of the region in guest physical memory */
> + uint64_t addr;
> +
> + /* usable region size (<= region_size) */
> + uint64_t usable_region_size;
> +
> + /* actual size (how much the guest plugged) */
> + uint64_t size;
> +
> + /* requested size */
> + uint64_t requested_size;
> +
> + /* block size and alignment */
> + uint64_t block_size;
> +} VirtIOMEM;
> +
> +typedef struct VirtIOMEMClass {
> + /* private */
> + VirtIODevice parent;
> +
> + /* public */
> + void (*fill_device_info)(const VirtIOMEM *vmen, VirtioMEMDeviceInfo *vi);
> + MemoryRegion *(*get_memory_region)(VirtIOMEM *vmem, Error **errp);
> +} VirtIOMEMClass;
> +
> +#endif
> diff --git a/qapi/misc.json b/qapi/misc.json
> index a5a0beb902..65ca3edf32 100644
> --- a/qapi/misc.json
> +++ b/qapi/misc.json
> @@ -1356,19 +1356,56 @@
> }
> }
>
> +##
> +# @VirtioMEMDeviceInfo:
> +#
> +# VirtioMEMDevice state information
> +#
> +# @id: device's ID
> +#
> +# @memaddr: physical address in memory, where device is mapped
> +#
> +# @requested-size: the user requested size of the device
> +#
> +# @size: the (current) size of memory that the device provides
> +#
> +# @max-size: the maximum size of memory that the device can provide
> +#
> +# @block-size: the block size of memory that the device provides
> +#
> +# @node: NUMA node number where device is assigned to
> +#
> +# @memdev: memory backend linked with the region
> +#
> +# Since: 5.1
> +##
> +{ 'struct': 'VirtioMEMDeviceInfo',
> + 'data': { '*id': 'str',
> + 'memaddr': 'size',
> + 'requested-size': 'size',
> + 'size': 'size',
> + 'max-size': 'size',
> + 'block-size': 'size',
> + 'node': 'int',
> + 'memdev': 'str'
> + }
> +}
> +
> ##
> # @MemoryDeviceInfo:
> #
> # Union containing information about a memory device
> #
> # nvdimm is included since 2.12. virtio-pmem is included since 4.1.
> +# virtio-mem is included since 5.1.
> #
> # Since: 2.1
> ##
> { 'union': 'MemoryDeviceInfo',
> 'data': { 'dimm': 'PCDIMMDeviceInfo',
> 'nvdimm': 'PCDIMMDeviceInfo',
> - 'virtio-pmem': 'VirtioPMEMDeviceInfo'
> + 'virtio-pmem': 'VirtioPMEMDeviceInfo',
> + 'virtio-mem': 'VirtioMEMDeviceInfo'
> }
> }
>
> --
> 2.26.2
^ permalink raw reply [flat|nested] 29+ messages in thread* Re: [PATCH v5 10/21] virtio-mem: Paravirtualized memory hot(un)plug
2020-06-30 10:06 ` Michael S. Tsirkin
@ 2020-06-30 10:21 ` David Hildenbrand
0 siblings, 0 replies; 29+ messages in thread
From: David Hildenbrand @ 2020-06-30 10:21 UTC (permalink / raw)
To: Michael S. Tsirkin
Cc: qemu-devel, kvm, qemu-s390x, Richard Henderson, Paolo Bonzini,
Dr . David Alan Gilbert, Eduardo Habkost, Eric Blake,
Markus Armbruster, Igor Mammedov
On 30.06.20 12:06, Michael S. Tsirkin wrote:
> On Fri, Jun 26, 2020 at 09:22:37AM +0200, David Hildenbrand wrote:
>> This is the very basic/initial version of virtio-mem. An introduction to
>> virtio-mem can be found in the Linux kernel driver [1]. While it can be
>> used in the current state for hotplug of a smaller amount of memory, it
>> will heavily benefit from resizeable memory regions in the future.
>>
>> Each virtio-mem device manages a memory region (provided via a memory
>> backend). After requested by the hypervisor ("requested-size"), the
>> guest can try to plug/unplug blocks of memory within that region, in order
>> to reach the requested size. Initially, and after a reboot, all memory is
>> unplugged (except in special cases - reboot during postcopy).
>>
>> The guest may only try to plug/unplug blocks of memory within the usable
>> region size. The usable region size is a little bigger than the
>> requested size, to give the device driver some flexibility. The usable
>> region size will only grow, except on reboots or when all memory is
>> requested to get unplugged. The guest can never plug more memory than
>> requested. Unplugged memory will get zapped/discarded, similar to in a
>> balloon device.
>>
>> The block size is variable, however, it is always chosen in a way such that
>> THP splits are avoided (e.g., 2MB). The state of each block
>> (plugged/unplugged) is tracked in a bitmap.
>>
>> As virtio-mem devices (e.g., virtio-mem-pci) will be memory devices, we now
>> expose "VirtioMEMDeviceInfo" via "query-memory-devices".
>>
>> --------------------------------------------------------------------------
>>
>> There are two important follow-up items that are in the works:
>> 1. Resizeable memory regions: Use resizeable allocations/RAM blocks to
>> grow/shrink along with the usable region size. This avoids creating
>> initially very big VMAs, RAM blocks, and KVM slots.
>> 2. Protection of unplugged memory: Make sure the gust cannot actually
>> make use of unplugged memory.
>>
>> Other follow-up items that are in the works:
>> 1. Exclude unplugged memory during migration (via precopy notifier).
>> 2. Handle remapping of memory.
>> 3. Support for other architectures.
>
> Question: I see that this does not check qemu_balloon_is_inhibited -
> is that because this works with VFIO, somehow?
> Or is this an oversight?
I use the new
if (ram_block_discard_require(true)) {
error_setg(errp, "Discarding RAM is disabled");
return;
}
in virtio_mem_device_realize. This will assure that incompatible
technologies (esp. VFIO) are inhibited and are not able to become active
as long as virtio-mem is around.
virtio_mem_is_busy() handles migration/postcopy, indicating "busy" while
migration is temporarily active.
(qemu_balloon_is_inhibited() is no more since "[PATCH v5 06/21]
virtio-balloon: Rip out qemu_balloon_inhibit()")
--
Thanks,
David / dhildenb
^ permalink raw reply [flat|nested] 29+ messages in thread
* [PATCH v5 11/21] virtio-pci: Proxy for virtio-mem
2020-06-26 7:22 [PATCH v5 00/21] virtio-mem: Paravirtualized memory hot(un)plug David Hildenbrand
` (9 preceding siblings ...)
2020-06-26 7:22 ` [PATCH v5 10/21] virtio-mem: Paravirtualized memory hot(un)plug David Hildenbrand
@ 2020-06-26 7:22 ` David Hildenbrand
2020-07-06 15:28 ` Cornelia Huck
2020-06-26 7:22 ` [PATCH v5 12/21] MAINTAINERS: Add myself as virtio-mem maintainer David Hildenbrand
` (10 subsequent siblings)
21 siblings, 1 reply; 29+ messages in thread
From: David Hildenbrand @ 2020-06-26 7:22 UTC (permalink / raw)
To: qemu-devel
Cc: kvm, qemu-s390x, Richard Henderson, Paolo Bonzini,
Dr . David Alan Gilbert, Eduardo Habkost, Michael S . Tsirkin,
David Hildenbrand, Pankaj Gupta, Marcel Apfelbaum, Igor Mammedov
Let's add a proxy for virtio-mem, make it a memory device, and
pass-through the properties.
Reviewed-by: Pankaj Gupta <pankaj.gupta.linux@gmail.com>
Cc: "Michael S. Tsirkin" <mst@redhat.com>
Cc: Marcel Apfelbaum <marcel.apfelbaum@gmail.com>
Cc: "Dr. David Alan Gilbert" <dgilbert@redhat.com>
Cc: Igor Mammedov <imammedo@redhat.com>
Signed-off-by: David Hildenbrand <david@redhat.com>
---
hw/virtio/Makefile.objs | 1 +
hw/virtio/virtio-mem-pci.c | 129 +++++++++++++++++++++++++++++++++++++
hw/virtio/virtio-mem-pci.h | 33 ++++++++++
include/hw/pci/pci.h | 1 +
4 files changed, 164 insertions(+)
create mode 100644 hw/virtio/virtio-mem-pci.c
create mode 100644 hw/virtio/virtio-mem-pci.h
diff --git a/hw/virtio/Makefile.objs b/hw/virtio/Makefile.objs
index f3a65e01b7..a986708186 100644
--- a/hw/virtio/Makefile.objs
+++ b/hw/virtio/Makefile.objs
@@ -20,6 +20,7 @@ obj-$(CONFIG_VIRTIO_IOMMU) += virtio-iommu.o
obj-$(CONFIG_VHOST_VSOCK) += vhost-vsock-common.o vhost-vsock.o
obj-$(CONFIG_VHOST_USER_VSOCK) += vhost-vsock-common.o vhost-user-vsock.o
obj-$(CONFIG_VIRTIO_MEM) += virtio-mem.o
+common-obj-$(call land,$(CONFIG_VIRTIO_MEM),$(CONFIG_VIRTIO_PCI)) += virtio-mem-pci.o
ifeq ($(CONFIG_VIRTIO_PCI),y)
obj-$(CONFIG_VHOST_VSOCK) += vhost-vsock-pci.o
diff --git a/hw/virtio/virtio-mem-pci.c b/hw/virtio/virtio-mem-pci.c
new file mode 100644
index 0000000000..b325303b32
--- /dev/null
+++ b/hw/virtio/virtio-mem-pci.c
@@ -0,0 +1,129 @@
+/*
+ * Virtio MEM PCI device
+ *
+ * Copyright (C) 2020 Red Hat, Inc.
+ *
+ * Authors:
+ * David Hildenbrand <david@redhat.com>
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2.
+ * See the COPYING file in the top-level directory.
+ */
+
+#include "qemu/osdep.h"
+#include "virtio-mem-pci.h"
+#include "hw/mem/memory-device.h"
+#include "qapi/error.h"
+
+static void virtio_mem_pci_realize(VirtIOPCIProxy *vpci_dev, Error **errp)
+{
+ VirtIOMEMPCI *mem_pci = VIRTIO_MEM_PCI(vpci_dev);
+ DeviceState *vdev = DEVICE(&mem_pci->vdev);
+
+ qdev_set_parent_bus(vdev, BUS(&vpci_dev->bus));
+ object_property_set_bool(OBJECT(vdev), true, "realized", errp);
+}
+
+static void virtio_mem_pci_set_addr(MemoryDeviceState *md, uint64_t addr,
+ Error **errp)
+{
+ object_property_set_uint(OBJECT(md), addr, VIRTIO_MEM_ADDR_PROP, errp);
+}
+
+static uint64_t virtio_mem_pci_get_addr(const MemoryDeviceState *md)
+{
+ return object_property_get_uint(OBJECT(md), VIRTIO_MEM_ADDR_PROP,
+ &error_abort);
+}
+
+static MemoryRegion *virtio_mem_pci_get_memory_region(MemoryDeviceState *md,
+ Error **errp)
+{
+ VirtIOMEMPCI *pci_mem = VIRTIO_MEM_PCI(md);
+ VirtIOMEM *vmem = VIRTIO_MEM(&pci_mem->vdev);
+ VirtIOMEMClass *vmc = VIRTIO_MEM_GET_CLASS(vmem);
+
+ return vmc->get_memory_region(vmem, errp);
+}
+
+static uint64_t virtio_mem_pci_get_plugged_size(const MemoryDeviceState *md,
+ Error **errp)
+{
+ return object_property_get_uint(OBJECT(md), VIRTIO_MEM_SIZE_PROP,
+ errp);
+}
+
+static void virtio_mem_pci_fill_device_info(const MemoryDeviceState *md,
+ MemoryDeviceInfo *info)
+{
+ VirtioMEMDeviceInfo *vi = g_new0(VirtioMEMDeviceInfo, 1);
+ VirtIOMEMPCI *pci_mem = VIRTIO_MEM_PCI(md);
+ VirtIOMEM *vmem = VIRTIO_MEM(&pci_mem->vdev);
+ VirtIOMEMClass *vpc = VIRTIO_MEM_GET_CLASS(vmem);
+ DeviceState *dev = DEVICE(md);
+
+ if (dev->id) {
+ vi->has_id = true;
+ vi->id = g_strdup(dev->id);
+ }
+
+ /* let the real device handle everything else */
+ vpc->fill_device_info(vmem, vi);
+
+ info->u.virtio_mem.data = vi;
+ info->type = MEMORY_DEVICE_INFO_KIND_VIRTIO_MEM;
+}
+
+static void virtio_mem_pci_class_init(ObjectClass *klass, void *data)
+{
+ DeviceClass *dc = DEVICE_CLASS(klass);
+ VirtioPCIClass *k = VIRTIO_PCI_CLASS(klass);
+ PCIDeviceClass *pcidev_k = PCI_DEVICE_CLASS(klass);
+ MemoryDeviceClass *mdc = MEMORY_DEVICE_CLASS(klass);
+
+ k->realize = virtio_mem_pci_realize;
+ set_bit(DEVICE_CATEGORY_MISC, dc->categories);
+ pcidev_k->vendor_id = PCI_VENDOR_ID_REDHAT_QUMRANET;
+ pcidev_k->device_id = PCI_DEVICE_ID_VIRTIO_MEM;
+ pcidev_k->revision = VIRTIO_PCI_ABI_VERSION;
+ pcidev_k->class_id = PCI_CLASS_OTHERS;
+
+ mdc->get_addr = virtio_mem_pci_get_addr;
+ mdc->set_addr = virtio_mem_pci_set_addr;
+ mdc->get_plugged_size = virtio_mem_pci_get_plugged_size;
+ mdc->get_memory_region = virtio_mem_pci_get_memory_region;
+ mdc->fill_device_info = virtio_mem_pci_fill_device_info;
+}
+
+static void virtio_mem_pci_instance_init(Object *obj)
+{
+ VirtIOMEMPCI *dev = VIRTIO_MEM_PCI(obj);
+
+ virtio_instance_init_common(obj, &dev->vdev, sizeof(dev->vdev),
+ TYPE_VIRTIO_MEM);
+ object_property_add_alias(obj, VIRTIO_MEM_BLOCK_SIZE_PROP,
+ OBJECT(&dev->vdev), VIRTIO_MEM_BLOCK_SIZE_PROP);
+ object_property_add_alias(obj, VIRTIO_MEM_SIZE_PROP, OBJECT(&dev->vdev),
+ VIRTIO_MEM_SIZE_PROP);
+ object_property_add_alias(obj, VIRTIO_MEM_REQUESTED_SIZE_PROP,
+ OBJECT(&dev->vdev),
+ VIRTIO_MEM_REQUESTED_SIZE_PROP);
+}
+
+static const VirtioPCIDeviceTypeInfo virtio_mem_pci_info = {
+ .base_name = TYPE_VIRTIO_MEM_PCI,
+ .generic_name = "virtio-mem-pci",
+ .instance_size = sizeof(VirtIOMEMPCI),
+ .instance_init = virtio_mem_pci_instance_init,
+ .class_init = virtio_mem_pci_class_init,
+ .interfaces = (InterfaceInfo[]) {
+ { TYPE_MEMORY_DEVICE },
+ { }
+ },
+};
+
+static void virtio_mem_pci_register_types(void)
+{
+ virtio_pci_types_register(&virtio_mem_pci_info);
+}
+type_init(virtio_mem_pci_register_types)
diff --git a/hw/virtio/virtio-mem-pci.h b/hw/virtio/virtio-mem-pci.h
new file mode 100644
index 0000000000..8820cd6628
--- /dev/null
+++ b/hw/virtio/virtio-mem-pci.h
@@ -0,0 +1,33 @@
+/*
+ * Virtio MEM PCI device
+ *
+ * Copyright (C) 2020 Red Hat, Inc.
+ *
+ * Authors:
+ * David Hildenbrand <david@redhat.com>
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2.
+ * See the COPYING file in the top-level directory.
+ */
+
+#ifndef QEMU_VIRTIO_MEM_PCI_H
+#define QEMU_VIRTIO_MEM_PCI_H
+
+#include "hw/virtio/virtio-pci.h"
+#include "hw/virtio/virtio-mem.h"
+
+typedef struct VirtIOMEMPCI VirtIOMEMPCI;
+
+/*
+ * virtio-mem-pci: This extends VirtioPCIProxy.
+ */
+#define TYPE_VIRTIO_MEM_PCI "virtio-mem-pci-base"
+#define VIRTIO_MEM_PCI(obj) \
+ OBJECT_CHECK(VirtIOMEMPCI, (obj), TYPE_VIRTIO_MEM_PCI)
+
+struct VirtIOMEMPCI {
+ VirtIOPCIProxy parent_obj;
+ VirtIOMEM vdev;
+};
+
+#endif /* QEMU_VIRTIO_MEM_PCI_H */
diff --git a/include/hw/pci/pci.h b/include/hw/pci/pci.h
index a4e9c33416..c1bf7d5356 100644
--- a/include/hw/pci/pci.h
+++ b/include/hw/pci/pci.h
@@ -87,6 +87,7 @@ extern bool pci_available;
#define PCI_DEVICE_ID_VIRTIO_VSOCK 0x1012
#define PCI_DEVICE_ID_VIRTIO_PMEM 0x1013
#define PCI_DEVICE_ID_VIRTIO_IOMMU 0x1014
+#define PCI_DEVICE_ID_VIRTIO_MEM 0x1015
#define PCI_VENDOR_ID_REDHAT 0x1b36
#define PCI_DEVICE_ID_REDHAT_BRIDGE 0x0001
--
2.26.2
^ permalink raw reply related [flat|nested] 29+ messages in thread* Re: [PATCH v5 11/21] virtio-pci: Proxy for virtio-mem
2020-06-26 7:22 ` [PATCH v5 11/21] virtio-pci: Proxy for virtio-mem David Hildenbrand
@ 2020-07-06 15:28 ` Cornelia Huck
2020-07-06 16:39 ` David Hildenbrand
0 siblings, 1 reply; 29+ messages in thread
From: Cornelia Huck @ 2020-07-06 15:28 UTC (permalink / raw)
To: David Hildenbrand
Cc: qemu-devel, Pankaj Gupta, Eduardo Habkost, kvm,
Michael S . Tsirkin, Dr . David Alan Gilbert, qemu-s390x,
Marcel Apfelbaum, Igor Mammedov, Paolo Bonzini,
Richard Henderson
On Fri, 26 Jun 2020 09:22:38 +0200
David Hildenbrand <david@redhat.com> wrote:
> Let's add a proxy for virtio-mem, make it a memory device, and
> pass-through the properties.
>
> Reviewed-by: Pankaj Gupta <pankaj.gupta.linux@gmail.com>
> Cc: "Michael S. Tsirkin" <mst@redhat.com>
> Cc: Marcel Apfelbaum <marcel.apfelbaum@gmail.com>
> Cc: "Dr. David Alan Gilbert" <dgilbert@redhat.com>
> Cc: Igor Mammedov <imammedo@redhat.com>
> Signed-off-by: David Hildenbrand <david@redhat.com>
> ---
> hw/virtio/Makefile.objs | 1 +
> hw/virtio/virtio-mem-pci.c | 129 +++++++++++++++++++++++++++++++++++++
> hw/virtio/virtio-mem-pci.h | 33 ++++++++++
> include/hw/pci/pci.h | 1 +
> 4 files changed, 164 insertions(+)
> create mode 100644 hw/virtio/virtio-mem-pci.c
> create mode 100644 hw/virtio/virtio-mem-pci.h
(...)
> diff --git a/hw/virtio/virtio-mem-pci.c b/hw/virtio/virtio-mem-pci.c
> new file mode 100644
> index 0000000000..b325303b32
> --- /dev/null
> +++ b/hw/virtio/virtio-mem-pci.c
> @@ -0,0 +1,129 @@
> +/*
> + * Virtio MEM PCI device
> + *
> + * Copyright (C) 2020 Red Hat, Inc.
> + *
> + * Authors:
> + * David Hildenbrand <david@redhat.com>
> + *
> + * This work is licensed under the terms of the GNU GPL, version 2.
> + * See the COPYING file in the top-level directory.
> + */
> +
> +#include "qemu/osdep.h"
> +#include "virtio-mem-pci.h"
> +#include "hw/mem/memory-device.h"
> +#include "qapi/error.h"
> +
> +static void virtio_mem_pci_realize(VirtIOPCIProxy *vpci_dev, Error **errp)
> +{
> + VirtIOMEMPCI *mem_pci = VIRTIO_MEM_PCI(vpci_dev);
> + DeviceState *vdev = DEVICE(&mem_pci->vdev);
> +
As we were having that discussion for other devices recently: I think
you want to use
virtio_pci_force_virtio_1(vpci_dev);
here. (Or do it via the names in the type, as virtio-fs does, but I
think I like forcing it better.)
> + qdev_set_parent_bus(vdev, BUS(&vpci_dev->bus));
> + object_property_set_bool(OBJECT(vdev), true, "realized", errp);
> +}
^ permalink raw reply [flat|nested] 29+ messages in thread* Re: [PATCH v5 11/21] virtio-pci: Proxy for virtio-mem
2020-07-06 15:28 ` Cornelia Huck
@ 2020-07-06 16:39 ` David Hildenbrand
0 siblings, 0 replies; 29+ messages in thread
From: David Hildenbrand @ 2020-07-06 16:39 UTC (permalink / raw)
To: Cornelia Huck
Cc: qemu-devel, Pankaj Gupta, Eduardo Habkost, kvm,
Michael S . Tsirkin, Dr . David Alan Gilbert, qemu-s390x,
Marcel Apfelbaum, Igor Mammedov, Paolo Bonzini,
Richard Henderson
On 06.07.20 17:28, Cornelia Huck wrote:
> On Fri, 26 Jun 2020 09:22:38 +0200
> David Hildenbrand <david@redhat.com> wrote:
>
>> Let's add a proxy for virtio-mem, make it a memory device, and
>> pass-through the properties.
>>
>> Reviewed-by: Pankaj Gupta <pankaj.gupta.linux@gmail.com>
>> Cc: "Michael S. Tsirkin" <mst@redhat.com>
>> Cc: Marcel Apfelbaum <marcel.apfelbaum@gmail.com>
>> Cc: "Dr. David Alan Gilbert" <dgilbert@redhat.com>
>> Cc: Igor Mammedov <imammedo@redhat.com>
>> Signed-off-by: David Hildenbrand <david@redhat.com>
>> ---
>> hw/virtio/Makefile.objs | 1 +
>> hw/virtio/virtio-mem-pci.c | 129 +++++++++++++++++++++++++++++++++++++
>> hw/virtio/virtio-mem-pci.h | 33 ++++++++++
>> include/hw/pci/pci.h | 1 +
>> 4 files changed, 164 insertions(+)
>> create mode 100644 hw/virtio/virtio-mem-pci.c
>> create mode 100644 hw/virtio/virtio-mem-pci.h
>
> (...)
>
>> diff --git a/hw/virtio/virtio-mem-pci.c b/hw/virtio/virtio-mem-pci.c
>> new file mode 100644
>> index 0000000000..b325303b32
>> --- /dev/null
>> +++ b/hw/virtio/virtio-mem-pci.c
>> @@ -0,0 +1,129 @@
>> +/*
>> + * Virtio MEM PCI device
>> + *
>> + * Copyright (C) 2020 Red Hat, Inc.
>> + *
>> + * Authors:
>> + * David Hildenbrand <david@redhat.com>
>> + *
>> + * This work is licensed under the terms of the GNU GPL, version 2.
>> + * See the COPYING file in the top-level directory.
>> + */
>> +
>> +#include "qemu/osdep.h"
>> +#include "virtio-mem-pci.h"
>> +#include "hw/mem/memory-device.h"
>> +#include "qapi/error.h"
>> +
>> +static void virtio_mem_pci_realize(VirtIOPCIProxy *vpci_dev, Error **errp)
>> +{
>> + VirtIOMEMPCI *mem_pci = VIRTIO_MEM_PCI(vpci_dev);
>> + DeviceState *vdev = DEVICE(&mem_pci->vdev);
>> +
>
> As we were having that discussion for other devices recently: I think
> you want to use
>
> virtio_pci_force_virtio_1(vpci_dev);
>
> here. (Or do it via the names in the type, as virtio-fs does, but I
> think I like forcing it better.)
Interesting. There is a PULL request pending which includes virtio-mem,
so I'll send that as an addon. Thanks!
--
Thanks,
David / dhildenb
^ permalink raw reply [flat|nested] 29+ messages in thread
* [PATCH v5 12/21] MAINTAINERS: Add myself as virtio-mem maintainer
2020-06-26 7:22 [PATCH v5 00/21] virtio-mem: Paravirtualized memory hot(un)plug David Hildenbrand
` (10 preceding siblings ...)
2020-06-26 7:22 ` [PATCH v5 11/21] virtio-pci: Proxy for virtio-mem David Hildenbrand
@ 2020-06-26 7:22 ` David Hildenbrand
2020-06-26 7:22 ` [PATCH v5 13/21] hmp: Handle virtio-mem when printing memory device info David Hildenbrand
` (9 subsequent siblings)
21 siblings, 0 replies; 29+ messages in thread
From: David Hildenbrand @ 2020-06-26 7:22 UTC (permalink / raw)
To: qemu-devel
Cc: kvm, qemu-s390x, Richard Henderson, Paolo Bonzini,
Dr . David Alan Gilbert, Eduardo Habkost, Michael S . Tsirkin,
David Hildenbrand, Peter Maydell, Markus Armbruster
Let's make sure patches/bug reports find the right person.
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Cc: "Michael S. Tsirkin" <mst@redhat.com>
Cc: Peter Maydell <peter.maydell@linaro.org>
Cc: Markus Armbruster <armbru@redhat.com>
Signed-off-by: David Hildenbrand <david@redhat.com>
---
MAINTAINERS | 9 +++++++++
1 file changed, 9 insertions(+)
diff --git a/MAINTAINERS b/MAINTAINERS
index 1b40446c73..3f7f583436 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -1784,6 +1784,15 @@ F: hw/virtio/virtio-crypto.c
F: hw/virtio/virtio-crypto-pci.c
F: include/hw/virtio/virtio-crypto.h
+virtio-mem
+M: David Hildenbrand <david@redhat.com>
+S: Supported
+W: https://virtio-mem.gitlab.io/
+F: hw/virtio/virtio-mem.c
+F: hw/virtio/virtio-mem-pci.h
+F: hw/virtio/virtio-mem-pci.c
+F: include/hw/virtio/virtio-mem.h
+
nvme
M: Keith Busch <kbusch@kernel.org>
L: qemu-block@nongnu.org
--
2.26.2
^ permalink raw reply related [flat|nested] 29+ messages in thread* [PATCH v5 13/21] hmp: Handle virtio-mem when printing memory device info
2020-06-26 7:22 [PATCH v5 00/21] virtio-mem: Paravirtualized memory hot(un)plug David Hildenbrand
` (11 preceding siblings ...)
2020-06-26 7:22 ` [PATCH v5 12/21] MAINTAINERS: Add myself as virtio-mem maintainer David Hildenbrand
@ 2020-06-26 7:22 ` David Hildenbrand
2020-06-26 7:22 ` [PATCH v5 14/21] numa: Handle virtio-mem in NUMA stats David Hildenbrand
` (8 subsequent siblings)
21 siblings, 0 replies; 29+ messages in thread
From: David Hildenbrand @ 2020-06-26 7:22 UTC (permalink / raw)
To: qemu-devel
Cc: kvm, qemu-s390x, Richard Henderson, Paolo Bonzini,
Dr . David Alan Gilbert, Eduardo Habkost, Michael S . Tsirkin,
David Hildenbrand
Print the memory device info just like for other memory devices.
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Cc: "Dr. David Alan Gilbert" <dgilbert@redhat.com>
Cc: "Michael S. Tsirkin" <mst@redhat.com>
Signed-off-by: David Hildenbrand <david@redhat.com>
---
monitor/hmp-cmds.c | 16 ++++++++++++++++
1 file changed, 16 insertions(+)
diff --git a/monitor/hmp-cmds.c b/monitor/hmp-cmds.c
index 2b0b58a336..2ec13e4cc3 100644
--- a/monitor/hmp-cmds.c
+++ b/monitor/hmp-cmds.c
@@ -1821,6 +1821,7 @@ void hmp_info_memory_devices(Monitor *mon, const QDict *qdict)
MemoryDeviceInfoList *info_list = qmp_query_memory_devices(&err);
MemoryDeviceInfoList *info;
VirtioPMEMDeviceInfo *vpi;
+ VirtioMEMDeviceInfo *vmi;
MemoryDeviceInfo *value;
PCDIMMDeviceInfo *di;
@@ -1855,6 +1856,21 @@ void hmp_info_memory_devices(Monitor *mon, const QDict *qdict)
monitor_printf(mon, " size: %" PRIu64 "\n", vpi->size);
monitor_printf(mon, " memdev: %s\n", vpi->memdev);
break;
+ case MEMORY_DEVICE_INFO_KIND_VIRTIO_MEM:
+ vmi = value->u.virtio_mem.data;
+ monitor_printf(mon, "Memory device [%s]: \"%s\"\n",
+ MemoryDeviceInfoKind_str(value->type),
+ vmi->id ? vmi->id : "");
+ monitor_printf(mon, " memaddr: 0x%" PRIx64 "\n", vmi->memaddr);
+ monitor_printf(mon, " node: %" PRId64 "\n", vmi->node);
+ monitor_printf(mon, " requested-size: %" PRIu64 "\n",
+ vmi->requested_size);
+ monitor_printf(mon, " size: %" PRIu64 "\n", vmi->size);
+ monitor_printf(mon, " max-size: %" PRIu64 "\n", vmi->max_size);
+ monitor_printf(mon, " block-size: %" PRIu64 "\n",
+ vmi->block_size);
+ monitor_printf(mon, " memdev: %s\n", vmi->memdev);
+ break;
default:
g_assert_not_reached();
}
--
2.26.2
^ permalink raw reply related [flat|nested] 29+ messages in thread* [PATCH v5 14/21] numa: Handle virtio-mem in NUMA stats
2020-06-26 7:22 [PATCH v5 00/21] virtio-mem: Paravirtualized memory hot(un)plug David Hildenbrand
` (12 preceding siblings ...)
2020-06-26 7:22 ` [PATCH v5 13/21] hmp: Handle virtio-mem when printing memory device info David Hildenbrand
@ 2020-06-26 7:22 ` David Hildenbrand
2020-06-26 7:22 ` [PATCH v5 15/21] pc: Support for virtio-mem-pci David Hildenbrand
` (7 subsequent siblings)
21 siblings, 0 replies; 29+ messages in thread
From: David Hildenbrand @ 2020-06-26 7:22 UTC (permalink / raw)
To: qemu-devel
Cc: kvm, qemu-s390x, Richard Henderson, Paolo Bonzini,
Dr . David Alan Gilbert, Eduardo Habkost, Michael S . Tsirkin,
David Hildenbrand, Pankaj Gupta, Marcel Apfelbaum
Account the memory to the configured nid.
Reviewed-by: Pankaj Gupta <pankaj.gupta.linux@gmail.com>
Cc: Eduardo Habkost <ehabkost@redhat.com>
Cc: Marcel Apfelbaum <marcel.apfelbaum@gmail.com>
Cc: "Michael S. Tsirkin" <mst@redhat.com>
Signed-off-by: David Hildenbrand <david@redhat.com>
---
hw/core/numa.c | 6 ++++++
1 file changed, 6 insertions(+)
diff --git a/hw/core/numa.c b/hw/core/numa.c
index 5f81900f88..ca0b2e5fa7 100644
--- a/hw/core/numa.c
+++ b/hw/core/numa.c
@@ -817,6 +817,7 @@ static void numa_stat_memory_devices(NumaNodeMem node_mem[])
MemoryDeviceInfoList *info;
PCDIMMDeviceInfo *pcdimm_info;
VirtioPMEMDeviceInfo *vpi;
+ VirtioMEMDeviceInfo *vmi;
for (info = info_list; info; info = info->next) {
MemoryDeviceInfo *value = info->value;
@@ -837,6 +838,11 @@ static void numa_stat_memory_devices(NumaNodeMem node_mem[])
node_mem[0].node_mem += vpi->size;
node_mem[0].node_plugged_mem += vpi->size;
break;
+ case MEMORY_DEVICE_INFO_KIND_VIRTIO_MEM:
+ vmi = value->u.virtio_mem.data;
+ node_mem[vmi->node].node_mem += vmi->size;
+ node_mem[vmi->node].node_plugged_mem += vmi->size;
+ break;
default:
g_assert_not_reached();
}
--
2.26.2
^ permalink raw reply related [flat|nested] 29+ messages in thread* [PATCH v5 15/21] pc: Support for virtio-mem-pci
2020-06-26 7:22 [PATCH v5 00/21] virtio-mem: Paravirtualized memory hot(un)plug David Hildenbrand
` (13 preceding siblings ...)
2020-06-26 7:22 ` [PATCH v5 14/21] numa: Handle virtio-mem in NUMA stats David Hildenbrand
@ 2020-06-26 7:22 ` David Hildenbrand
2020-06-26 7:22 ` [PATCH v5 16/21] virtio-mem: Allow notifiers for size changes David Hildenbrand
` (6 subsequent siblings)
21 siblings, 0 replies; 29+ messages in thread
From: David Hildenbrand @ 2020-06-26 7:22 UTC (permalink / raw)
To: qemu-devel
Cc: kvm, qemu-s390x, Richard Henderson, Paolo Bonzini,
Dr . David Alan Gilbert, Eduardo Habkost, Michael S . Tsirkin,
David Hildenbrand, Pankaj Gupta, Marcel Apfelbaum, Eric Blake,
Markus Armbruster
Let's wire it up similar to virtio-pmem. Also disallow unplug, so it's
harder for users to shoot themselves into the foot.
Reviewed-by: Pankaj Gupta <pankaj.gupta.linux@gmail.com>
Cc: "Michael S. Tsirkin" <mst@redhat.com>
Cc: Marcel Apfelbaum <marcel.apfelbaum@gmail.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Richard Henderson <rth@twiddle.net>
Cc: Eduardo Habkost <ehabkost@redhat.com>
Cc: Eric Blake <eblake@redhat.com>
Cc: Markus Armbruster <armbru@redhat.com>
Signed-off-by: David Hildenbrand <david@redhat.com>
---
hw/i386/Kconfig | 1 +
hw/i386/pc.c | 49 ++++++++++++++++++++++++++++---------------------
2 files changed, 29 insertions(+), 21 deletions(-)
diff --git a/hw/i386/Kconfig b/hw/i386/Kconfig
index c93f32f657..03e347b207 100644
--- a/hw/i386/Kconfig
+++ b/hw/i386/Kconfig
@@ -35,6 +35,7 @@ config PC
select ACPI_PCI
select ACPI_VMGENID
select VIRTIO_PMEM_SUPPORTED
+ select VIRTIO_MEM_SUPPORTED
config PC_PCI
bool
diff --git a/hw/i386/pc.c b/hw/i386/pc.c
index 2dfd69b973..f2a18a3276 100644
--- a/hw/i386/pc.c
+++ b/hw/i386/pc.c
@@ -88,6 +88,7 @@
#include "hw/net/ne2000-isa.h"
#include "standard-headers/asm-x86/bootparam.h"
#include "hw/virtio/virtio-pmem-pci.h"
+#include "hw/virtio/virtio-mem-pci.h"
#include "hw/mem/memory-device.h"
#include "sysemu/replay.h"
#include "qapi/qmp/qerror.h"
@@ -1637,8 +1638,8 @@ static void pc_cpu_pre_plug(HotplugHandler *hotplug_dev,
numa_cpu_pre_plug(cpu_slot, dev, errp);
}
-static void pc_virtio_pmem_pci_pre_plug(HotplugHandler *hotplug_dev,
- DeviceState *dev, Error **errp)
+static void pc_virtio_md_pci_pre_plug(HotplugHandler *hotplug_dev,
+ DeviceState *dev, Error **errp)
{
HotplugHandler *hotplug_dev2 = qdev_get_bus_hotplug_handler(dev);
Error *local_err = NULL;
@@ -1649,7 +1650,8 @@ static void pc_virtio_pmem_pci_pre_plug(HotplugHandler *hotplug_dev,
* order. We should never reach this point when hotplugging on x86,
* however, better add a safety net.
*/
- error_setg(errp, "virtio-pmem-pci hotplug not supported on this bus.");
+ error_setg(errp, "hotplug of virtio based memory devices not supported"
+ " on this bus.");
return;
}
/*
@@ -1664,8 +1666,8 @@ static void pc_virtio_pmem_pci_pre_plug(HotplugHandler *hotplug_dev,
error_propagate(errp, local_err);
}
-static void pc_virtio_pmem_pci_plug(HotplugHandler *hotplug_dev,
- DeviceState *dev, Error **errp)
+static void pc_virtio_md_pci_plug(HotplugHandler *hotplug_dev,
+ DeviceState *dev, Error **errp)
{
HotplugHandler *hotplug_dev2 = qdev_get_bus_hotplug_handler(dev);
Error *local_err = NULL;
@@ -1685,17 +1687,17 @@ static void pc_virtio_pmem_pci_plug(HotplugHandler *hotplug_dev,
error_propagate(errp, local_err);
}
-static void pc_virtio_pmem_pci_unplug_request(HotplugHandler *hotplug_dev,
- DeviceState *dev, Error **errp)
+static void pc_virtio_md_pci_unplug_request(HotplugHandler *hotplug_dev,
+ DeviceState *dev, Error **errp)
{
- /* We don't support virtio pmem hot unplug */
- error_setg(errp, "virtio pmem device unplug not supported.");
+ /* We don't support hot unplug of virtio based memory devices */
+ error_setg(errp, "virtio based memory devices cannot be unplugged.");
}
-static void pc_virtio_pmem_pci_unplug(HotplugHandler *hotplug_dev,
- DeviceState *dev, Error **errp)
+static void pc_virtio_md_pci_unplug(HotplugHandler *hotplug_dev,
+ DeviceState *dev, Error **errp)
{
- /* We don't support virtio pmem hot unplug */
+ /* We don't support hot unplug of virtio based memory devices */
}
static void pc_machine_device_pre_plug_cb(HotplugHandler *hotplug_dev,
@@ -1705,8 +1707,9 @@ static void pc_machine_device_pre_plug_cb(HotplugHandler *hotplug_dev,
pc_memory_pre_plug(hotplug_dev, dev, errp);
} else if (object_dynamic_cast(OBJECT(dev), TYPE_CPU)) {
pc_cpu_pre_plug(hotplug_dev, dev, errp);
- } else if (object_dynamic_cast(OBJECT(dev), TYPE_VIRTIO_PMEM_PCI)) {
- pc_virtio_pmem_pci_pre_plug(hotplug_dev, dev, errp);
+ } else if (object_dynamic_cast(OBJECT(dev), TYPE_VIRTIO_PMEM_PCI) ||
+ object_dynamic_cast(OBJECT(dev), TYPE_VIRTIO_MEM_PCI)) {
+ pc_virtio_md_pci_pre_plug(hotplug_dev, dev, errp);
}
}
@@ -1717,8 +1720,9 @@ static void pc_machine_device_plug_cb(HotplugHandler *hotplug_dev,
pc_memory_plug(hotplug_dev, dev, errp);
} else if (object_dynamic_cast(OBJECT(dev), TYPE_CPU)) {
pc_cpu_plug(hotplug_dev, dev, errp);
- } else if (object_dynamic_cast(OBJECT(dev), TYPE_VIRTIO_PMEM_PCI)) {
- pc_virtio_pmem_pci_plug(hotplug_dev, dev, errp);
+ } else if (object_dynamic_cast(OBJECT(dev), TYPE_VIRTIO_PMEM_PCI) ||
+ object_dynamic_cast(OBJECT(dev), TYPE_VIRTIO_MEM_PCI)) {
+ pc_virtio_md_pci_plug(hotplug_dev, dev, errp);
}
}
@@ -1729,8 +1733,9 @@ static void pc_machine_device_unplug_request_cb(HotplugHandler *hotplug_dev,
pc_memory_unplug_request(hotplug_dev, dev, errp);
} else if (object_dynamic_cast(OBJECT(dev), TYPE_CPU)) {
pc_cpu_unplug_request_cb(hotplug_dev, dev, errp);
- } else if (object_dynamic_cast(OBJECT(dev), TYPE_VIRTIO_PMEM_PCI)) {
- pc_virtio_pmem_pci_unplug_request(hotplug_dev, dev, errp);
+ } else if (object_dynamic_cast(OBJECT(dev), TYPE_VIRTIO_PMEM_PCI) ||
+ object_dynamic_cast(OBJECT(dev), TYPE_VIRTIO_MEM_PCI)) {
+ pc_virtio_md_pci_unplug_request(hotplug_dev, dev, errp);
} else {
error_setg(errp, "acpi: device unplug request for not supported device"
" type: %s", object_get_typename(OBJECT(dev)));
@@ -1744,8 +1749,9 @@ static void pc_machine_device_unplug_cb(HotplugHandler *hotplug_dev,
pc_memory_unplug(hotplug_dev, dev, errp);
} else if (object_dynamic_cast(OBJECT(dev), TYPE_CPU)) {
pc_cpu_unplug_cb(hotplug_dev, dev, errp);
- } else if (object_dynamic_cast(OBJECT(dev), TYPE_VIRTIO_PMEM_PCI)) {
- pc_virtio_pmem_pci_unplug(hotplug_dev, dev, errp);
+ } else if (object_dynamic_cast(OBJECT(dev), TYPE_VIRTIO_PMEM_PCI) ||
+ object_dynamic_cast(OBJECT(dev), TYPE_VIRTIO_MEM_PCI)) {
+ pc_virtio_md_pci_unplug(hotplug_dev, dev, errp);
} else {
error_setg(errp, "acpi: device unplug for not supported device"
" type: %s", object_get_typename(OBJECT(dev)));
@@ -1757,7 +1763,8 @@ static HotplugHandler *pc_get_hotplug_handler(MachineState *machine,
{
if (object_dynamic_cast(OBJECT(dev), TYPE_PC_DIMM) ||
object_dynamic_cast(OBJECT(dev), TYPE_CPU) ||
- object_dynamic_cast(OBJECT(dev), TYPE_VIRTIO_PMEM_PCI)) {
+ object_dynamic_cast(OBJECT(dev), TYPE_VIRTIO_PMEM_PCI) ||
+ object_dynamic_cast(OBJECT(dev), TYPE_VIRTIO_MEM_PCI)) {
return HOTPLUG_HANDLER(machine);
}
--
2.26.2
^ permalink raw reply related [flat|nested] 29+ messages in thread* [PATCH v5 16/21] virtio-mem: Allow notifiers for size changes
2020-06-26 7:22 [PATCH v5 00/21] virtio-mem: Paravirtualized memory hot(un)plug David Hildenbrand
` (14 preceding siblings ...)
2020-06-26 7:22 ` [PATCH v5 15/21] pc: Support for virtio-mem-pci David Hildenbrand
@ 2020-06-26 7:22 ` David Hildenbrand
2020-06-26 7:22 ` [PATCH v5 17/21] virtio-pci: Send qapi events when the virtio-mem " David Hildenbrand
` (5 subsequent siblings)
21 siblings, 0 replies; 29+ messages in thread
From: David Hildenbrand @ 2020-06-26 7:22 UTC (permalink / raw)
To: qemu-devel
Cc: kvm, qemu-s390x, Richard Henderson, Paolo Bonzini,
Dr . David Alan Gilbert, Eduardo Habkost, Michael S . Tsirkin,
David Hildenbrand, Igor Mammedov
We want to send qapi events in case the size of a virtio-mem device
changes. This allows upper layers to always know how much memory is
actually currently consumed via a virtio-mem device.
Unfortuantely, we have to report the id of our proxy device. Let's provide
an easy way for our proxy device to register, so it can send the qapi
events. Piggy-backing on the notifier infrastructure (although we'll
only ever have one notifier registered) seems to be an easy way.
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Cc: "Michael S. Tsirkin" <mst@redhat.com>
Cc: "Dr. David Alan Gilbert" <dgilbert@redhat.com>
Cc: Igor Mammedov <imammedo@redhat.com>
Signed-off-by: David Hildenbrand <david@redhat.com>
---
hw/virtio/virtio-mem.c | 21 ++++++++++++++++++++-
include/hw/virtio/virtio-mem.h | 5 +++++
2 files changed, 25 insertions(+), 1 deletion(-)
diff --git a/hw/virtio/virtio-mem.c b/hw/virtio/virtio-mem.c
index d8a0c974d3..2df33f9125 100644
--- a/hw/virtio/virtio-mem.c
+++ b/hw/virtio/virtio-mem.c
@@ -184,6 +184,7 @@ static int virtio_mem_state_change_request(VirtIOMEM *vmem, uint64_t gpa,
} else {
vmem->size -= size;
}
+ notifier_list_notify(&vmem->size_change_notifiers, &vmem->size);
return VIRTIO_MEM_RESP_ACK;
}
@@ -242,7 +243,10 @@ static int virtio_mem_unplug_all(VirtIOMEM *vmem)
return -EBUSY;
}
bitmap_clear(vmem->bitmap, 0, vmem->bitmap_size);
- vmem->size = 0;
+ if (vmem->size) {
+ vmem->size = 0;
+ notifier_list_notify(&vmem->size_change_notifiers, &vmem->size);
+ }
virtio_mem_resize_usable_region(vmem, vmem->requested_size, true);
return 0;
@@ -561,6 +565,18 @@ static MemoryRegion *virtio_mem_get_memory_region(VirtIOMEM *vmem, Error **errp)
return &vmem->memdev->mr;
}
+static void virtio_mem_add_size_change_notifier(VirtIOMEM *vmem,
+ Notifier *notifier)
+{
+ notifier_list_add(&vmem->size_change_notifiers, notifier);
+}
+
+static void virtio_mem_remove_size_change_notifier(VirtIOMEM *vmem,
+ Notifier *notifier)
+{
+ notifier_remove(notifier);
+}
+
static void virtio_mem_get_size(Object *obj, Visitor *v, const char *name,
void *opaque, Error **errp)
{
@@ -668,6 +684,7 @@ static void virtio_mem_instance_init(Object *obj)
VirtIOMEM *vmem = VIRTIO_MEM(obj);
vmem->block_size = VIRTIO_MEM_MIN_BLOCK_SIZE;
+ notifier_list_init(&vmem->size_change_notifiers);
object_property_add(obj, VIRTIO_MEM_SIZE_PROP, "size", virtio_mem_get_size,
NULL, NULL, NULL);
@@ -705,6 +722,8 @@ static void virtio_mem_class_init(ObjectClass *klass, void *data)
vmc->fill_device_info = virtio_mem_fill_device_info;
vmc->get_memory_region = virtio_mem_get_memory_region;
+ vmc->add_size_change_notifier = virtio_mem_add_size_change_notifier;
+ vmc->remove_size_change_notifier = virtio_mem_remove_size_change_notifier;
}
static const TypeInfo virtio_mem_info = {
diff --git a/include/hw/virtio/virtio-mem.h b/include/hw/virtio/virtio-mem.h
index 6981096f7c..b74c77cd42 100644
--- a/include/hw/virtio/virtio-mem.h
+++ b/include/hw/virtio/virtio-mem.h
@@ -64,6 +64,9 @@ typedef struct VirtIOMEM {
/* block size and alignment */
uint64_t block_size;
+
+ /* notifiers to notify when "size" changes */
+ NotifierList size_change_notifiers;
} VirtIOMEM;
typedef struct VirtIOMEMClass {
@@ -73,6 +76,8 @@ typedef struct VirtIOMEMClass {
/* public */
void (*fill_device_info)(const VirtIOMEM *vmen, VirtioMEMDeviceInfo *vi);
MemoryRegion *(*get_memory_region)(VirtIOMEM *vmem, Error **errp);
+ void (*add_size_change_notifier)(VirtIOMEM *vmem, Notifier *notifier);
+ void (*remove_size_change_notifier)(VirtIOMEM *vmem, Notifier *notifier);
} VirtIOMEMClass;
#endif
--
2.26.2
^ permalink raw reply related [flat|nested] 29+ messages in thread* [PATCH v5 17/21] virtio-pci: Send qapi events when the virtio-mem size changes
2020-06-26 7:22 [PATCH v5 00/21] virtio-mem: Paravirtualized memory hot(un)plug David Hildenbrand
` (15 preceding siblings ...)
2020-06-26 7:22 ` [PATCH v5 16/21] virtio-mem: Allow notifiers for size changes David Hildenbrand
@ 2020-06-26 7:22 ` David Hildenbrand
2020-06-26 7:22 ` [PATCH v5 18/21] virtio-mem: Migration sanity checks David Hildenbrand
` (4 subsequent siblings)
21 siblings, 0 replies; 29+ messages in thread
From: David Hildenbrand @ 2020-06-26 7:22 UTC (permalink / raw)
To: qemu-devel
Cc: kvm, qemu-s390x, Richard Henderson, Paolo Bonzini,
Dr . David Alan Gilbert, Eduardo Habkost, Michael S . Tsirkin,
David Hildenbrand, Markus Armbruster, Eric Blake, Igor Mammedov
Let's register the notifier and trigger the qapi event with the right
device id.
MEMORY_DEVICE_SIZE_CHANGE is similar to BALLOON_CHANGE, however on a
memory device level.
Don't unregister the notifier (we neither have finalize() nor unrealize()
for VirtIOPCIProxy, so it's not that simple to do it) - both devices are
expected to vanish at the same time.
Cc: "Michael S. Tsirkin" <mst@redhat.com>
Cc: Markus Armbruster <armbru@redhat.com>
Cc: "Dr. David Alan Gilbert" <dgilbert@redhat.com>
Cc: Eric Blake <eblake@redhat.com>
Cc: Igor Mammedov <imammedo@redhat.com>
Signed-off-by: David Hildenbrand <david@redhat.com>
---
hw/virtio/virtio-mem-pci.c | 28 ++++++++++++++++++++++++++++
hw/virtio/virtio-mem-pci.h | 1 +
monitor/monitor.c | 1 +
qapi/misc.json | 25 +++++++++++++++++++++++++
4 files changed, 55 insertions(+)
diff --git a/hw/virtio/virtio-mem-pci.c b/hw/virtio/virtio-mem-pci.c
index b325303b32..1a8e854123 100644
--- a/hw/virtio/virtio-mem-pci.c
+++ b/hw/virtio/virtio-mem-pci.c
@@ -14,6 +14,7 @@
#include "virtio-mem-pci.h"
#include "hw/mem/memory-device.h"
#include "qapi/error.h"
+#include "qapi/qapi-events-misc.h"
static void virtio_mem_pci_realize(VirtIOPCIProxy *vpci_dev, Error **errp)
{
@@ -74,6 +75,21 @@ static void virtio_mem_pci_fill_device_info(const MemoryDeviceState *md,
info->type = MEMORY_DEVICE_INFO_KIND_VIRTIO_MEM;
}
+static void virtio_mem_pci_size_change_notify(Notifier *notifier, void *data)
+{
+ VirtIOMEMPCI *pci_mem = container_of(notifier, VirtIOMEMPCI,
+ size_change_notifier);
+ DeviceState *dev = DEVICE(pci_mem);
+ const uint64_t * const size_p = data;
+ const char *id = NULL;
+
+ if (dev->id) {
+ id = g_strdup(dev->id);
+ }
+
+ qapi_event_send_memory_device_size_change(!!id, id, *size_p);
+}
+
static void virtio_mem_pci_class_init(ObjectClass *klass, void *data)
{
DeviceClass *dc = DEVICE_CLASS(klass);
@@ -98,9 +114,21 @@ static void virtio_mem_pci_class_init(ObjectClass *klass, void *data)
static void virtio_mem_pci_instance_init(Object *obj)
{
VirtIOMEMPCI *dev = VIRTIO_MEM_PCI(obj);
+ VirtIOMEMClass *vmc;
+ VirtIOMEM *vmem;
virtio_instance_init_common(obj, &dev->vdev, sizeof(dev->vdev),
TYPE_VIRTIO_MEM);
+
+ dev->size_change_notifier.notify = virtio_mem_pci_size_change_notify;
+ vmem = VIRTIO_MEM(&dev->vdev);
+ vmc = VIRTIO_MEM_GET_CLASS(vmem);
+ /*
+ * We never remove the notifier again, as we expect both devices to
+ * disappear at the same time.
+ */
+ vmc->add_size_change_notifier(vmem, &dev->size_change_notifier);
+
object_property_add_alias(obj, VIRTIO_MEM_BLOCK_SIZE_PROP,
OBJECT(&dev->vdev), VIRTIO_MEM_BLOCK_SIZE_PROP);
object_property_add_alias(obj, VIRTIO_MEM_SIZE_PROP, OBJECT(&dev->vdev),
diff --git a/hw/virtio/virtio-mem-pci.h b/hw/virtio/virtio-mem-pci.h
index 8820cd6628..b51a28b275 100644
--- a/hw/virtio/virtio-mem-pci.h
+++ b/hw/virtio/virtio-mem-pci.h
@@ -28,6 +28,7 @@ typedef struct VirtIOMEMPCI VirtIOMEMPCI;
struct VirtIOMEMPCI {
VirtIOPCIProxy parent_obj;
VirtIOMEM vdev;
+ Notifier size_change_notifier;
};
#endif /* QEMU_VIRTIO_MEM_PCI_H */
diff --git a/monitor/monitor.c b/monitor/monitor.c
index 125494410a..19dcb8fbe3 100644
--- a/monitor/monitor.c
+++ b/monitor/monitor.c
@@ -235,6 +235,7 @@ static MonitorQAPIEventConf monitor_qapi_event_conf[QAPI_EVENT__MAX] = {
[QAPI_EVENT_QUORUM_REPORT_BAD] = { 1000 * SCALE_MS },
[QAPI_EVENT_QUORUM_FAILURE] = { 1000 * SCALE_MS },
[QAPI_EVENT_VSERPORT_CHANGE] = { 1000 * SCALE_MS },
+ [QAPI_EVENT_MEMORY_DEVICE_SIZE_CHANGE] = { 1000 * SCALE_MS },
};
/*
diff --git a/qapi/misc.json b/qapi/misc.json
index 65ca3edf32..149c925246 100644
--- a/qapi/misc.json
+++ b/qapi/misc.json
@@ -1434,6 +1434,31 @@
##
{ 'command': 'query-memory-devices', 'returns': ['MemoryDeviceInfo'] }
+##
+# @MEMORY_DEVICE_SIZE_CHANGE:
+#
+# Emitted when the size of a memory device changes. Only emitted for memory
+# devices that can actually change the size (e.g., virtio-mem due to guest
+# action).
+#
+# @id: device's ID
+# @size: the new size of memory that the device provides
+#
+# Note: this event is rate-limited.
+#
+# Since: 5.1
+#
+# Example:
+#
+# <- { "event": "MEMORY_DEVICE_SIZE_CHANGE",
+# "data": { "id": "vm0", "size": 1073741824},
+# "timestamp": { "seconds": 1588168529, "microseconds": 201316 } }
+#
+##
+{ 'event': 'MEMORY_DEVICE_SIZE_CHANGE',
+ 'data': { '*id': 'str', 'size': 'size' } }
+
+
##
# @MEM_UNPLUG_ERROR:
#
--
2.26.2
^ permalink raw reply related [flat|nested] 29+ messages in thread* [PATCH v5 18/21] virtio-mem: Migration sanity checks
2020-06-26 7:22 [PATCH v5 00/21] virtio-mem: Paravirtualized memory hot(un)plug David Hildenbrand
` (16 preceding siblings ...)
2020-06-26 7:22 ` [PATCH v5 17/21] virtio-pci: Send qapi events when the virtio-mem " David Hildenbrand
@ 2020-06-26 7:22 ` David Hildenbrand
2020-06-26 7:22 ` [PATCH v5 19/21] virtio-mem: Add trace events David Hildenbrand
` (3 subsequent siblings)
21 siblings, 0 replies; 29+ messages in thread
From: David Hildenbrand @ 2020-06-26 7:22 UTC (permalink / raw)
To: qemu-devel
Cc: kvm, qemu-s390x, Richard Henderson, Paolo Bonzini,
Dr . David Alan Gilbert, Eduardo Habkost, Michael S . Tsirkin,
David Hildenbrand
We want to make sure that certain properties don't change during
migration, especially to catch user errors in a nice way. Let's migrate
a temporary structure and validate that the properties didn't change.
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Cc: "Michael S. Tsirkin" <mst@redhat.com>
Cc: "Dr. David Alan Gilbert" <dgilbert@redhat.com>
Signed-off-by: David Hildenbrand <david@redhat.com>
---
hw/virtio/virtio-mem.c | 70 ++++++++++++++++++++++++++++++++++++++++++
1 file changed, 70 insertions(+)
diff --git a/hw/virtio/virtio-mem.c b/hw/virtio/virtio-mem.c
index 2df33f9125..6ed5409669 100644
--- a/hw/virtio/virtio-mem.c
+++ b/hw/virtio/virtio-mem.c
@@ -519,12 +519,82 @@ static int virtio_mem_post_load(void *opaque, int version_id)
return virtio_mem_restore_unplugged(VIRTIO_MEM(opaque));
}
+typedef struct VirtIOMEMMigSanityChecks {
+ VirtIOMEM *parent;
+ uint64_t addr;
+ uint64_t region_size;
+ uint64_t block_size;
+ uint32_t node;
+} VirtIOMEMMigSanityChecks;
+
+static int virtio_mem_mig_sanity_checks_pre_save(void *opaque)
+{
+ VirtIOMEMMigSanityChecks *tmp = opaque;
+ VirtIOMEM *vmem = tmp->parent;
+
+ tmp->addr = vmem->addr;
+ tmp->region_size = memory_region_size(&vmem->memdev->mr);
+ tmp->block_size = vmem->block_size;
+ tmp->node = vmem->node;
+ return 0;
+}
+
+static int virtio_mem_mig_sanity_checks_post_load(void *opaque, int version_id)
+{
+ VirtIOMEMMigSanityChecks *tmp = opaque;
+ VirtIOMEM *vmem = tmp->parent;
+ const uint64_t new_region_size = memory_region_size(&vmem->memdev->mr);
+
+ if (tmp->addr != vmem->addr) {
+ error_report("Property '%s' changed from 0x%" PRIx64 " to 0x%" PRIx64,
+ VIRTIO_MEM_ADDR_PROP, tmp->addr, vmem->addr);
+ return -EINVAL;
+ }
+ /*
+ * Note: Preparation for resizeable memory regions. The maximum size
+ * of the memory region must not change during migration.
+ */
+ if (tmp->region_size != new_region_size) {
+ error_report("Property '%s' size changed from 0x%" PRIx64 " to 0x%"
+ PRIx64, VIRTIO_MEM_MEMDEV_PROP, tmp->region_size,
+ new_region_size);
+ return -EINVAL;
+ }
+ if (tmp->block_size != vmem->block_size) {
+ error_report("Property '%s' changed from 0x%" PRIx64 " to 0x%" PRIx64,
+ VIRTIO_MEM_BLOCK_SIZE_PROP, tmp->block_size,
+ vmem->block_size);
+ return -EINVAL;
+ }
+ if (tmp->node != vmem->node) {
+ error_report("Property '%s' changed from %" PRIu32 " to %" PRIu32,
+ VIRTIO_MEM_NODE_PROP, tmp->node, vmem->node);
+ return -EINVAL;
+ }
+ return 0;
+}
+
+static const VMStateDescription vmstate_virtio_mem_sanity_checks = {
+ .name = "virtio-mem-device/sanity-checks",
+ .pre_save = virtio_mem_mig_sanity_checks_pre_save,
+ .post_load = virtio_mem_mig_sanity_checks_post_load,
+ .fields = (VMStateField[]) {
+ VMSTATE_UINT64(addr, VirtIOMEMMigSanityChecks),
+ VMSTATE_UINT64(region_size, VirtIOMEMMigSanityChecks),
+ VMSTATE_UINT64(block_size, VirtIOMEMMigSanityChecks),
+ VMSTATE_UINT32(node, VirtIOMEMMigSanityChecks),
+ VMSTATE_END_OF_LIST(),
+ },
+};
+
static const VMStateDescription vmstate_virtio_mem_device = {
.name = "virtio-mem-device",
.minimum_version_id = 1,
.version_id = 1,
.post_load = virtio_mem_post_load,
.fields = (VMStateField[]) {
+ VMSTATE_WITH_TMP(VirtIOMEM, VirtIOMEMMigSanityChecks,
+ vmstate_virtio_mem_sanity_checks),
VMSTATE_UINT64(usable_region_size, VirtIOMEM),
VMSTATE_UINT64(size, VirtIOMEM),
VMSTATE_UINT64(requested_size, VirtIOMEM),
--
2.26.2
^ permalink raw reply related [flat|nested] 29+ messages in thread* [PATCH v5 19/21] virtio-mem: Add trace events
2020-06-26 7:22 [PATCH v5 00/21] virtio-mem: Paravirtualized memory hot(un)plug David Hildenbrand
` (17 preceding siblings ...)
2020-06-26 7:22 ` [PATCH v5 18/21] virtio-mem: Migration sanity checks David Hildenbrand
@ 2020-06-26 7:22 ` David Hildenbrand
2020-07-02 19:08 ` Dr. David Alan Gilbert
2020-06-26 7:22 ` [PATCH v5 20/21] virtio-mem: Exclude unplugged memory during migration David Hildenbrand
` (2 subsequent siblings)
21 siblings, 1 reply; 29+ messages in thread
From: David Hildenbrand @ 2020-06-26 7:22 UTC (permalink / raw)
To: qemu-devel
Cc: kvm, qemu-s390x, Richard Henderson, Paolo Bonzini,
Dr . David Alan Gilbert, Eduardo Habkost, Michael S . Tsirkin,
David Hildenbrand
Let's add some trace events that might come in handy later.
Cc: "Michael S. Tsirkin" <mst@redhat.com>
Cc: "Dr. David Alan Gilbert" <dgilbert@redhat.com>
Signed-off-by: David Hildenbrand <david@redhat.com>
---
hw/virtio/trace-events | 10 ++++++++++
hw/virtio/virtio-mem.c | 10 +++++++++-
2 files changed, 19 insertions(+), 1 deletion(-)
diff --git a/hw/virtio/trace-events b/hw/virtio/trace-events
index 6427a0047d..292fc15e29 100644
--- a/hw/virtio/trace-events
+++ b/hw/virtio/trace-events
@@ -74,3 +74,13 @@ virtio_iommu_get_domain(uint32_t domain_id) "Alloc domain=%d"
virtio_iommu_put_domain(uint32_t domain_id) "Free domain=%d"
virtio_iommu_translate_out(uint64_t virt_addr, uint64_t phys_addr, uint32_t sid) "0x%"PRIx64" -> 0x%"PRIx64 " for sid=%d"
virtio_iommu_report_fault(uint8_t reason, uint32_t flags, uint32_t endpoint, uint64_t addr) "FAULT reason=%d flags=%d endpoint=%d address =0x%"PRIx64
+
+# virtio-mem.c
+virtio_mem_send_response(uint16_t type) "type=%" PRIu16
+virtio_mem_plug_request(uint64_t addr, uint16_t nb_blocks) "addr=0x%" PRIx64 " nb_blocks=%" PRIu16
+virtio_mem_unplug_request(uint64_t addr, uint16_t nb_blocks) "addr=0x%" PRIx64 " nb_blocks=%" PRIu16
+virtio_mem_unplugged_all(void) ""
+virtio_mem_unplug_all_request(void) ""
+virtio_mem_resized_usable_region(uint64_t old_size, uint64_t new_size) "old_size=0x%" PRIx64 "new_size=0x%" PRIx64
+virtio_mem_state_request(uint64_t addr, uint16_t nb_blocks) "addr=0x%" PRIx64 " nb_blocks=%" PRIu16
+virtio_mem_state_response(uint16_t state) "state=%" PRIu16
diff --git a/hw/virtio/virtio-mem.c b/hw/virtio/virtio-mem.c
index 6ed5409669..fdd4dbb42c 100644
--- a/hw/virtio/virtio-mem.c
+++ b/hw/virtio/virtio-mem.c
@@ -30,6 +30,7 @@
#include "hw/boards.h"
#include "hw/qdev-properties.h"
#include "config-devices.h"
+#include "trace.h"
/*
* Use QEMU_VMALLOC_ALIGN, so no THP will have to be split when unplugging
@@ -100,6 +101,7 @@ static void virtio_mem_send_response(VirtIOMEM *vmem, VirtQueueElement *elem,
VirtIODevice *vdev = VIRTIO_DEVICE(vmem);
VirtQueue *vq = vmem->vq;
+ trace_virtio_mem_send_response(le16_to_cpu(resp->type));
iov_from_buf(elem->in_sg, elem->in_num, 0, resp, sizeof(*resp));
virtqueue_push(vq, elem, sizeof(*resp));
@@ -195,6 +197,7 @@ static void virtio_mem_plug_request(VirtIOMEM *vmem, VirtQueueElement *elem,
const uint16_t nb_blocks = le16_to_cpu(req->u.plug.nb_blocks);
uint16_t type;
+ trace_virtio_mem_plug_request(gpa, nb_blocks);
type = virtio_mem_state_change_request(vmem, gpa, nb_blocks, true);
virtio_mem_send_response_simple(vmem, elem, type);
}
@@ -206,6 +209,7 @@ static void virtio_mem_unplug_request(VirtIOMEM *vmem, VirtQueueElement *elem,
const uint16_t nb_blocks = le16_to_cpu(req->u.unplug.nb_blocks);
uint16_t type;
+ trace_virtio_mem_unplug_request(gpa, nb_blocks);
type = virtio_mem_state_change_request(vmem, gpa, nb_blocks, false);
virtio_mem_send_response_simple(vmem, elem, type);
}
@@ -225,6 +229,7 @@ static void virtio_mem_resize_usable_region(VirtIOMEM *vmem,
return;
}
+ trace_virtio_mem_resized_usable_region(vmem->usable_region_size, newsize);
vmem->usable_region_size = newsize;
}
@@ -247,7 +252,7 @@ static int virtio_mem_unplug_all(VirtIOMEM *vmem)
vmem->size = 0;
notifier_list_notify(&vmem->size_change_notifiers, &vmem->size);
}
-
+ trace_virtio_mem_unplugged_all();
virtio_mem_resize_usable_region(vmem, vmem->requested_size, true);
return 0;
}
@@ -255,6 +260,7 @@ static int virtio_mem_unplug_all(VirtIOMEM *vmem)
static void virtio_mem_unplug_all_request(VirtIOMEM *vmem,
VirtQueueElement *elem)
{
+ trace_virtio_mem_unplug_all_request();
if (virtio_mem_unplug_all(vmem)) {
virtio_mem_send_response_simple(vmem, elem, VIRTIO_MEM_RESP_BUSY);
} else {
@@ -272,6 +278,7 @@ static void virtio_mem_state_request(VirtIOMEM *vmem, VirtQueueElement *elem,
.type = cpu_to_le16(VIRTIO_MEM_RESP_ACK),
};
+ trace_virtio_mem_state_request(gpa, nb_blocks);
if (!virtio_mem_valid_range(vmem, gpa, size)) {
virtio_mem_send_response_simple(vmem, elem, VIRTIO_MEM_RESP_ERROR);
return;
@@ -284,6 +291,7 @@ static void virtio_mem_state_request(VirtIOMEM *vmem, VirtQueueElement *elem,
} else {
resp.u.state.state = cpu_to_le16(VIRTIO_MEM_STATE_MIXED);
}
+ trace_virtio_mem_state_response(le16_to_cpu(resp.u.state.state));
virtio_mem_send_response(vmem, elem, &resp);
}
--
2.26.2
^ permalink raw reply related [flat|nested] 29+ messages in thread* Re: [PATCH v5 19/21] virtio-mem: Add trace events
2020-06-26 7:22 ` [PATCH v5 19/21] virtio-mem: Add trace events David Hildenbrand
@ 2020-07-02 19:08 ` Dr. David Alan Gilbert
0 siblings, 0 replies; 29+ messages in thread
From: Dr. David Alan Gilbert @ 2020-07-02 19:08 UTC (permalink / raw)
To: David Hildenbrand
Cc: qemu-devel, kvm, qemu-s390x, Richard Henderson, Paolo Bonzini,
Eduardo Habkost, Michael S . Tsirkin
* David Hildenbrand (david@redhat.com) wrote:
> Let's add some trace events that might come in handy later.
>
> Cc: "Michael S. Tsirkin" <mst@redhat.com>
> Cc: "Dr. David Alan Gilbert" <dgilbert@redhat.com>
> Signed-off-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
> ---
> hw/virtio/trace-events | 10 ++++++++++
> hw/virtio/virtio-mem.c | 10 +++++++++-
> 2 files changed, 19 insertions(+), 1 deletion(-)
>
> diff --git a/hw/virtio/trace-events b/hw/virtio/trace-events
> index 6427a0047d..292fc15e29 100644
> --- a/hw/virtio/trace-events
> +++ b/hw/virtio/trace-events
> @@ -74,3 +74,13 @@ virtio_iommu_get_domain(uint32_t domain_id) "Alloc domain=%d"
> virtio_iommu_put_domain(uint32_t domain_id) "Free domain=%d"
> virtio_iommu_translate_out(uint64_t virt_addr, uint64_t phys_addr, uint32_t sid) "0x%"PRIx64" -> 0x%"PRIx64 " for sid=%d"
> virtio_iommu_report_fault(uint8_t reason, uint32_t flags, uint32_t endpoint, uint64_t addr) "FAULT reason=%d flags=%d endpoint=%d address =0x%"PRIx64
> +
> +# virtio-mem.c
> +virtio_mem_send_response(uint16_t type) "type=%" PRIu16
> +virtio_mem_plug_request(uint64_t addr, uint16_t nb_blocks) "addr=0x%" PRIx64 " nb_blocks=%" PRIu16
> +virtio_mem_unplug_request(uint64_t addr, uint16_t nb_blocks) "addr=0x%" PRIx64 " nb_blocks=%" PRIu16
> +virtio_mem_unplugged_all(void) ""
> +virtio_mem_unplug_all_request(void) ""
> +virtio_mem_resized_usable_region(uint64_t old_size, uint64_t new_size) "old_size=0x%" PRIx64 "new_size=0x%" PRIx64
> +virtio_mem_state_request(uint64_t addr, uint16_t nb_blocks) "addr=0x%" PRIx64 " nb_blocks=%" PRIu16
> +virtio_mem_state_response(uint16_t state) "state=%" PRIu16
> diff --git a/hw/virtio/virtio-mem.c b/hw/virtio/virtio-mem.c
> index 6ed5409669..fdd4dbb42c 100644
> --- a/hw/virtio/virtio-mem.c
> +++ b/hw/virtio/virtio-mem.c
> @@ -30,6 +30,7 @@
> #include "hw/boards.h"
> #include "hw/qdev-properties.h"
> #include "config-devices.h"
> +#include "trace.h"
>
> /*
> * Use QEMU_VMALLOC_ALIGN, so no THP will have to be split when unplugging
> @@ -100,6 +101,7 @@ static void virtio_mem_send_response(VirtIOMEM *vmem, VirtQueueElement *elem,
> VirtIODevice *vdev = VIRTIO_DEVICE(vmem);
> VirtQueue *vq = vmem->vq;
>
> + trace_virtio_mem_send_response(le16_to_cpu(resp->type));
> iov_from_buf(elem->in_sg, elem->in_num, 0, resp, sizeof(*resp));
>
> virtqueue_push(vq, elem, sizeof(*resp));
> @@ -195,6 +197,7 @@ static void virtio_mem_plug_request(VirtIOMEM *vmem, VirtQueueElement *elem,
> const uint16_t nb_blocks = le16_to_cpu(req->u.plug.nb_blocks);
> uint16_t type;
>
> + trace_virtio_mem_plug_request(gpa, nb_blocks);
> type = virtio_mem_state_change_request(vmem, gpa, nb_blocks, true);
> virtio_mem_send_response_simple(vmem, elem, type);
> }
> @@ -206,6 +209,7 @@ static void virtio_mem_unplug_request(VirtIOMEM *vmem, VirtQueueElement *elem,
> const uint16_t nb_blocks = le16_to_cpu(req->u.unplug.nb_blocks);
> uint16_t type;
>
> + trace_virtio_mem_unplug_request(gpa, nb_blocks);
> type = virtio_mem_state_change_request(vmem, gpa, nb_blocks, false);
> virtio_mem_send_response_simple(vmem, elem, type);
> }
> @@ -225,6 +229,7 @@ static void virtio_mem_resize_usable_region(VirtIOMEM *vmem,
> return;
> }
>
> + trace_virtio_mem_resized_usable_region(vmem->usable_region_size, newsize);
> vmem->usable_region_size = newsize;
> }
>
> @@ -247,7 +252,7 @@ static int virtio_mem_unplug_all(VirtIOMEM *vmem)
> vmem->size = 0;
> notifier_list_notify(&vmem->size_change_notifiers, &vmem->size);
> }
> -
> + trace_virtio_mem_unplugged_all();
> virtio_mem_resize_usable_region(vmem, vmem->requested_size, true);
> return 0;
> }
> @@ -255,6 +260,7 @@ static int virtio_mem_unplug_all(VirtIOMEM *vmem)
> static void virtio_mem_unplug_all_request(VirtIOMEM *vmem,
> VirtQueueElement *elem)
> {
> + trace_virtio_mem_unplug_all_request();
> if (virtio_mem_unplug_all(vmem)) {
> virtio_mem_send_response_simple(vmem, elem, VIRTIO_MEM_RESP_BUSY);
> } else {
> @@ -272,6 +278,7 @@ static void virtio_mem_state_request(VirtIOMEM *vmem, VirtQueueElement *elem,
> .type = cpu_to_le16(VIRTIO_MEM_RESP_ACK),
> };
>
> + trace_virtio_mem_state_request(gpa, nb_blocks);
> if (!virtio_mem_valid_range(vmem, gpa, size)) {
> virtio_mem_send_response_simple(vmem, elem, VIRTIO_MEM_RESP_ERROR);
> return;
> @@ -284,6 +291,7 @@ static void virtio_mem_state_request(VirtIOMEM *vmem, VirtQueueElement *elem,
> } else {
> resp.u.state.state = cpu_to_le16(VIRTIO_MEM_STATE_MIXED);
> }
> + trace_virtio_mem_state_response(le16_to_cpu(resp.u.state.state));
> virtio_mem_send_response(vmem, elem, &resp);
> }
>
> --
> 2.26.2
>
--
Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK
^ permalink raw reply [flat|nested] 29+ messages in thread
* [PATCH v5 20/21] virtio-mem: Exclude unplugged memory during migration
2020-06-26 7:22 [PATCH v5 00/21] virtio-mem: Paravirtualized memory hot(un)plug David Hildenbrand
` (18 preceding siblings ...)
2020-06-26 7:22 ` [PATCH v5 19/21] virtio-mem: Add trace events David Hildenbrand
@ 2020-06-26 7:22 ` David Hildenbrand
2020-06-26 7:22 ` [PATCH v5 21/21] numa: Auto-enable NUMA when any memory devices are possible David Hildenbrand
2020-07-03 10:40 ` [PATCH v1] virtio-mem: fix cross-compilation due to VIRTIO_MEM_USABLE_EXTENT David Hildenbrand
21 siblings, 0 replies; 29+ messages in thread
From: David Hildenbrand @ 2020-06-26 7:22 UTC (permalink / raw)
To: qemu-devel
Cc: kvm, qemu-s390x, Richard Henderson, Paolo Bonzini,
Dr . David Alan Gilbert, Eduardo Habkost, Michael S . Tsirkin,
David Hildenbrand
The content of unplugged memory is undefined and should not be migrated,
ever. Exclude all unplugged memory during precopy using the precopy notifier
infrastructure introduced for free page hinting in virtio-balloon.
Unplugged memory is marked as "not dirty", meaning it won't be
considered for migration.
Cc: "Michael S. Tsirkin" <mst@redhat.com>
Cc: "Dr. David Alan Gilbert" <dgilbert@redhat.com>
Signed-off-by: David Hildenbrand <david@redhat.com>
---
hw/virtio/virtio-mem.c | 54 +++++++++++++++++++++++++++++++++-
include/hw/virtio/virtio-mem.h | 3 ++
2 files changed, 56 insertions(+), 1 deletion(-)
diff --git a/hw/virtio/virtio-mem.c b/hw/virtio/virtio-mem.c
index fdd4dbb42c..bf9b414522 100644
--- a/hw/virtio/virtio-mem.c
+++ b/hw/virtio/virtio-mem.c
@@ -62,8 +62,14 @@ static bool virtio_mem_is_busy(void)
/*
* Postcopy cannot handle concurrent discards and we don't want to migrate
* pages on-demand with stale content when plugging new blocks.
+ *
+ * For precopy, we don't want unplugged blocks in our migration stream, and
+ * when plugging new blocks, the page content might differ between source
+ * and destination (observable by the guest when not initializing pages
+ * after plugging them) until we're running on the destination (as we didn't
+ * migrate these blocks when they were unplugged).
*/
- return migration_in_incoming_postcopy();
+ return migration_in_incoming_postcopy() || !migration_is_idle();
}
static bool virtio_mem_test_bitmap(VirtIOMEM *vmem, uint64_t start_gpa,
@@ -475,6 +481,7 @@ static void virtio_mem_device_realize(DeviceState *dev, Error **errp)
host_memory_backend_set_mapped(vmem->memdev, true);
vmstate_register_ram(&vmem->memdev->mr, DEVICE(vmem));
qemu_register_reset(virtio_mem_system_reset, vmem);
+ precopy_add_notifier(&vmem->precopy_notifier);
}
static void virtio_mem_device_unrealize(DeviceState *dev)
@@ -482,6 +489,7 @@ static void virtio_mem_device_unrealize(DeviceState *dev)
VirtIODevice *vdev = VIRTIO_DEVICE(dev);
VirtIOMEM *vmem = VIRTIO_MEM(dev);
+ precopy_remove_notifier(&vmem->precopy_notifier);
qemu_unregister_reset(virtio_mem_system_reset, vmem);
vmstate_unregister_ram(&vmem->memdev->mr, DEVICE(vmem));
host_memory_backend_set_mapped(vmem->memdev, false);
@@ -757,12 +765,56 @@ static void virtio_mem_set_block_size(Object *obj, Visitor *v, const char *name,
vmem->block_size = value;
}
+static void virtio_mem_precopy_exclude_unplugged(VirtIOMEM *vmem)
+{
+ void * const host = qemu_ram_get_host_addr(vmem->memdev->mr.ram_block);
+ unsigned long first_zero_bit, last_zero_bit;
+ uint64_t offset, length;
+
+ /*
+ * Find consecutive unplugged blocks and exclude them from migration.
+ *
+ * Note: Blocks cannot get (un)plugged during precopy, no locking needed.
+ */
+ first_zero_bit = find_first_zero_bit(vmem->bitmap, vmem->bitmap_size);
+ while (first_zero_bit < vmem->bitmap_size) {
+ offset = first_zero_bit * vmem->block_size;
+ last_zero_bit = find_next_bit(vmem->bitmap, vmem->bitmap_size,
+ first_zero_bit + 1) - 1;
+ length = (last_zero_bit - first_zero_bit + 1) * vmem->block_size;
+
+ qemu_guest_free_page_hint(host + offset, length);
+ first_zero_bit = find_next_zero_bit(vmem->bitmap, vmem->bitmap_size,
+ last_zero_bit + 2);
+ }
+}
+
+static int virtio_mem_precopy_notify(NotifierWithReturn *n, void *data)
+{
+ VirtIOMEM *vmem = container_of(n, VirtIOMEM, precopy_notifier);
+ PrecopyNotifyData *pnd = data;
+
+ switch (pnd->reason) {
+ case PRECOPY_NOTIFY_SETUP:
+ precopy_enable_free_page_optimization();
+ break;
+ case PRECOPY_NOTIFY_AFTER_BITMAP_SYNC:
+ virtio_mem_precopy_exclude_unplugged(vmem);
+ break;
+ default:
+ break;
+ }
+
+ return 0;
+}
+
static void virtio_mem_instance_init(Object *obj)
{
VirtIOMEM *vmem = VIRTIO_MEM(obj);
vmem->block_size = VIRTIO_MEM_MIN_BLOCK_SIZE;
notifier_list_init(&vmem->size_change_notifiers);
+ vmem->precopy_notifier.notify = virtio_mem_precopy_notify;
object_property_add(obj, VIRTIO_MEM_SIZE_PROP, "size", virtio_mem_get_size,
NULL, NULL, NULL);
diff --git a/include/hw/virtio/virtio-mem.h b/include/hw/virtio/virtio-mem.h
index b74c77cd42..0778224964 100644
--- a/include/hw/virtio/virtio-mem.h
+++ b/include/hw/virtio/virtio-mem.h
@@ -67,6 +67,9 @@ typedef struct VirtIOMEM {
/* notifiers to notify when "size" changes */
NotifierList size_change_notifiers;
+
+ /* don't migrate unplugged memory */
+ NotifierWithReturn precopy_notifier;
} VirtIOMEM;
typedef struct VirtIOMEMClass {
--
2.26.2
^ permalink raw reply related [flat|nested] 29+ messages in thread* [PATCH v5 21/21] numa: Auto-enable NUMA when any memory devices are possible
2020-06-26 7:22 [PATCH v5 00/21] virtio-mem: Paravirtualized memory hot(un)plug David Hildenbrand
` (19 preceding siblings ...)
2020-06-26 7:22 ` [PATCH v5 20/21] virtio-mem: Exclude unplugged memory during migration David Hildenbrand
@ 2020-06-26 7:22 ` David Hildenbrand
2020-07-03 10:40 ` [PATCH v1] virtio-mem: fix cross-compilation due to VIRTIO_MEM_USABLE_EXTENT David Hildenbrand
21 siblings, 0 replies; 29+ messages in thread
From: David Hildenbrand @ 2020-06-26 7:22 UTC (permalink / raw)
To: qemu-devel
Cc: kvm, qemu-s390x, Richard Henderson, Paolo Bonzini,
Dr . David Alan Gilbert, Eduardo Habkost, Michael S . Tsirkin,
David Hildenbrand, Alex Shi, Peter Maydell, Marcel Apfelbaum,
Sergio Lopez, Igor Mammedov, qemu-arm @ nongnu . org
Let's auto-enable it also when maxmem is specified but no slots are
defined. This will result in us properly creating ACPI srat tables,
indicating the maximum possible PFN to the guest OS. Based on this, e.g.,
Linux will enable the swiotlb properly.
This avoids having to manually force the switolb on (swiotlb=force) in
Linux in case we're booting only using DMA memory (e.g., 2GB on x86-64),
and virtio-mem adds memory later on that really needs the swiotlb to be
used for DMA.
Let's take care of backwards compatibility if somebody has a setup that
specifies "maxram" without "slots".
Reported-by: Alex Shi <alex.shi@linux.alibaba.com>
Cc: Peter Maydell <peter.maydell@linaro.org>
Cc: Eduardo Habkost <ehabkost@redhat.com>
Cc: Marcel Apfelbaum <marcel.apfelbaum@gmail.com>
Cc: Sergio Lopez <slp@redhat.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Richard Henderson <rth@twiddle.net>
Cc: "Michael S. Tsirkin" <mst@redhat.com>
Cc: Igor Mammedov <imammedo@redhat.com>
Cc: qemu-arm@nongnu.org <qemu-arm@nongnu.org>
Signed-off-by: David Hildenbrand <david@redhat.com>
---
hw/arm/virt.c | 2 ++
hw/core/numa.c | 11 ++++++-----
hw/i386/microvm.c | 1 +
hw/i386/pc.c | 1 +
hw/i386/pc_piix.c | 1 +
hw/i386/pc_q35.c | 1 +
include/hw/boards.h | 1 +
7 files changed, 13 insertions(+), 5 deletions(-)
diff --git a/hw/arm/virt.c b/hw/arm/virt.c
index 402c362c14..3865804681 100644
--- a/hw/arm/virt.c
+++ b/hw/arm/virt.c
@@ -2323,6 +2323,7 @@ static void virt_machine_class_init(ObjectClass *oc, void *data)
mc->numa_mem_supported = true;
mc->nvdimm_supported = true;
mc->auto_enable_numa_with_memhp = true;
+ mc->auto_enable_numa_with_memdev = true;
mc->default_ram_id = "mach-virt.ram";
object_class_property_add(oc, "acpi", "OnOffAuto",
@@ -2434,6 +2435,7 @@ static void virt_machine_5_0_options(MachineClass *mc)
{
virt_machine_5_1_options(mc);
compat_props_add(mc->compat_props, hw_compat_5_0, hw_compat_5_0_len);
+ mc->auto_enable_numa_with_memdev = false;
}
DEFINE_VIRT_MACHINE(5, 0)
diff --git a/hw/core/numa.c b/hw/core/numa.c
index ca0b2e5fa7..a78fc4e59e 100644
--- a/hw/core/numa.c
+++ b/hw/core/numa.c
@@ -681,8 +681,9 @@ void numa_complete_configuration(MachineState *ms)
NodeInfo *numa_info = ms->numa_state->nodes;
/*
- * If memory hotplug is enabled (slots > 0) but without '-numa'
- * options explicitly on CLI, guestes will break.
+ * If memory hotplug is enabled (slot > 0) or memory devices are enabled
+ * (ms->maxram_size > ram_size) but without '-numa' options explicitly on
+ * CLI, guests will break.
*
* Windows: won't enable memory hotplug without SRAT table at all
*
@@ -697,9 +698,9 @@ void numa_complete_configuration(MachineState *ms)
* assume there is just one node with whole RAM.
*/
if (ms->numa_state->num_nodes == 0 &&
- ((ms->ram_slots > 0 &&
- mc->auto_enable_numa_with_memhp) ||
- mc->auto_enable_numa)) {
+ ((ms->ram_slots && mc->auto_enable_numa_with_memhp) ||
+ (ms->maxram_size > ms->ram_size && mc->auto_enable_numa_with_memdev) ||
+ mc->auto_enable_numa)) {
NumaNodeOptions node = { };
parse_numa_node(ms, &node, &error_abort);
numa_info[0].node_mem = ram_size;
diff --git a/hw/i386/microvm.c b/hw/i386/microvm.c
index 5e931975a0..81d0888930 100644
--- a/hw/i386/microvm.c
+++ b/hw/i386/microvm.c
@@ -464,6 +464,7 @@ static void microvm_class_init(ObjectClass *oc, void *data)
mc->max_cpus = 288;
mc->has_hotpluggable_cpus = false;
mc->auto_enable_numa_with_memhp = false;
+ mc->auto_enable_numa_with_memdev = false;
mc->default_cpu_type = TARGET_DEFAULT_CPU_TYPE;
mc->nvdimm_supported = false;
mc->default_ram_id = "microvm.ram";
diff --git a/hw/i386/pc.c b/hw/i386/pc.c
index f2a18a3276..bc36a4efe7 100644
--- a/hw/i386/pc.c
+++ b/hw/i386/pc.c
@@ -1975,6 +1975,7 @@ static void pc_machine_class_init(ObjectClass *oc, void *data)
mc->get_default_cpu_node_id = x86_get_default_cpu_node_id;
mc->possible_cpu_arch_ids = x86_possible_cpu_arch_ids;
mc->auto_enable_numa_with_memhp = true;
+ mc->auto_enable_numa_with_memdev = true;
mc->has_hotpluggable_cpus = true;
mc->default_boot_order = "cad";
mc->hot_add_cpu = pc_hot_add_cpu;
diff --git a/hw/i386/pc_piix.c b/hw/i386/pc_piix.c
index 1497d0e4ae..33f3b58f3d 100644
--- a/hw/i386/pc_piix.c
+++ b/hw/i386/pc_piix.c
@@ -443,6 +443,7 @@ static void pc_i440fx_5_0_machine_options(MachineClass *m)
m->is_default = false;
compat_props_add(m->compat_props, hw_compat_5_0, hw_compat_5_0_len);
compat_props_add(m->compat_props, pc_compat_5_0, pc_compat_5_0_len);
+ m->auto_enable_numa_with_memdev = false;
}
DEFINE_I440FX_MACHINE(v5_0, "pc-i440fx-5.0", NULL,
diff --git a/hw/i386/pc_q35.c b/hw/i386/pc_q35.c
index 46cd06524c..d831b3359a 100644
--- a/hw/i386/pc_q35.c
+++ b/hw/i386/pc_q35.c
@@ -371,6 +371,7 @@ static void pc_q35_5_0_machine_options(MachineClass *m)
m->alias = NULL;
compat_props_add(m->compat_props, hw_compat_5_0, hw_compat_5_0_len);
compat_props_add(m->compat_props, pc_compat_5_0, pc_compat_5_0_len);
+ m->auto_enable_numa_with_memhp = false;
}
DEFINE_Q35_MACHINE(v5_0, "pc-q35-5.0", NULL,
diff --git a/include/hw/boards.h b/include/hw/boards.h
index 18815d9be2..426ce5f625 100644
--- a/include/hw/boards.h
+++ b/include/hw/boards.h
@@ -207,6 +207,7 @@ struct MachineClass {
const char **valid_cpu_types;
strList *allowed_dynamic_sysbus_devices;
bool auto_enable_numa_with_memhp;
+ bool auto_enable_numa_with_memdev;
void (*numa_auto_assign_ram)(MachineClass *mc, NodeInfo *nodes,
int nb_nodes, ram_addr_t size);
bool ignore_boot_device_suffixes;
--
2.26.2
^ permalink raw reply related [flat|nested] 29+ messages in thread* [PATCH v1] virtio-mem: fix cross-compilation due to VIRTIO_MEM_USABLE_EXTENT
2020-06-26 7:22 [PATCH v5 00/21] virtio-mem: Paravirtualized memory hot(un)plug David Hildenbrand
` (20 preceding siblings ...)
2020-06-26 7:22 ` [PATCH v5 21/21] numa: Auto-enable NUMA when any memory devices are possible David Hildenbrand
@ 2020-07-03 10:40 ` David Hildenbrand
2020-07-03 11:57 ` Michael S. Tsirkin
21 siblings, 1 reply; 29+ messages in thread
From: David Hildenbrand @ 2020-07-03 10:40 UTC (permalink / raw)
To: qemu-devel
Cc: kvm, David Hildenbrand, Michael S. Tsirkin,
Dr. David Alan Gilbert, Pankaj Gupta
The usable extend depends on the target, not on the destination. This
fixes cross-compilation on other architectures than x86-64.
Cc: "Michael S. Tsirkin" <mst@redhat.com>
Cc: "Dr. David Alan Gilbert" <dgilbert@redhat.com>
Cc: Pankaj Gupta <pankaj.gupta.linux@gmail.com>
Signed-off-by: David Hildenbrand <david@redhat.com>
---
hw/virtio/virtio-mem.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/hw/virtio/virtio-mem.c b/hw/virtio/virtio-mem.c
index bf9b414522..65850530e7 100644
--- a/hw/virtio/virtio-mem.c
+++ b/hw/virtio/virtio-mem.c
@@ -51,7 +51,7 @@
* necessary (as the section size can change). But it's more likely that the
* section size will rather get smaller and not bigger over time.
*/
-#if defined(__x86_64__)
+#if defined(TARGET_X86_64) || defined(TARGET_I386)
#define VIRTIO_MEM_USABLE_EXTENT (2 * (128 * MiB))
#else
#error VIRTIO_MEM_USABLE_EXTENT not defined
--
2.26.2
^ permalink raw reply related [flat|nested] 29+ messages in thread* Re: [PATCH v1] virtio-mem: fix cross-compilation due to VIRTIO_MEM_USABLE_EXTENT
2020-07-03 10:40 ` [PATCH v1] virtio-mem: fix cross-compilation due to VIRTIO_MEM_USABLE_EXTENT David Hildenbrand
@ 2020-07-03 11:57 ` Michael S. Tsirkin
0 siblings, 0 replies; 29+ messages in thread
From: Michael S. Tsirkin @ 2020-07-03 11:57 UTC (permalink / raw)
To: David Hildenbrand; +Cc: qemu-devel, kvm, Dr. David Alan Gilbert, Pankaj Gupta
On Fri, Jul 03, 2020 at 12:40:27PM +0200, David Hildenbrand wrote:
> The usable extend depends on the target, not on the destination. This
> fixes cross-compilation on other architectures than x86-64.
>
> Cc: "Michael S. Tsirkin" <mst@redhat.com>
> Cc: "Dr. David Alan Gilbert" <dgilbert@redhat.com>
> Cc: Pankaj Gupta <pankaj.gupta.linux@gmail.com>
> Signed-off-by: David Hildenbrand <david@redhat.com>
I folded this into 890f95d1adc8e0cb9fe88f74d1b76aad6d2763d6.
Thanks!
> ---
> hw/virtio/virtio-mem.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/hw/virtio/virtio-mem.c b/hw/virtio/virtio-mem.c
> index bf9b414522..65850530e7 100644
> --- a/hw/virtio/virtio-mem.c
> +++ b/hw/virtio/virtio-mem.c
> @@ -51,7 +51,7 @@
> * necessary (as the section size can change). But it's more likely that the
> * section size will rather get smaller and not bigger over time.
> */
> -#if defined(__x86_64__)
> +#if defined(TARGET_X86_64) || defined(TARGET_I386)
> #define VIRTIO_MEM_USABLE_EXTENT (2 * (128 * MiB))
> #else
> #error VIRTIO_MEM_USABLE_EXTENT not defined
> --
> 2.26.2
^ permalink raw reply [flat|nested] 29+ messages in thread