Re: [libvirt] [PATCH v2 20/20] qemu: ensure that memory 'discard' is used if specified in XML

2018-08-10 Thread Pavel Hrdina 
On Fri, Aug 10, 2018 at 09:26:27AM +0200, Michal Privoznik wrote:
> On 08/09/2018 02:38 PM, Pavel Hrdina wrote:
> > Signed-off-by: Pavel Hrdina 
> > ---
> >  src/qemu/qemu_command.c|  4 +++-
> >  .../pages-discard-hugepages.args   | 11 +++
> >  tests/qemuxml2argvdata/pages-discard.args  | 18 ++
> >  3 files changed, 24 insertions(+), 9 deletions(-)
> > 
> > diff --git a/src/qemu/qemu_command.c b/src/qemu/qemu_command.c
> > index dbeb3a54f6..a7859feae6 100644
> > --- a/src/qemu/qemu_command.c
> > +++ b/src/qemu/qemu_command.c
> > @@ -3147,6 +3147,7 @@ qemuBuildMemoryBackendProps(virJSONValuePtr 
> > *backendProps,
> >  return -1;
> >  
> >  if (useHugepage || mem->nvdimmPath || memAccess ||
> > +discard == VIR_TRISTATE_BOOL_YES ||
> >  def->mem.source == VIR_DOMAIN_MEMORY_SOURCE_FILE) {
> >  
> >  if (useHugepage) {
> > @@ -3228,7 +3229,8 @@ qemuBuildMemoryBackendProps(virJSONValuePtr 
> > *backendProps,
> >  if (!needHugepage && !mem->sourceNodes && !nodeSpecified &&
> >  !mem->nvdimmPath &&
> >  memAccess == VIR_DOMAIN_MEMORY_ACCESS_DEFAULT &&
> > -def->mem.source != VIR_DOMAIN_MEMORY_SOURCE_FILE && !force) {
> > +def->mem.source != VIR_DOMAIN_MEMORY_SOURCE_FILE && !force &&
> > +discard != VIR_TRISTATE_BOOL_YES) {
> >  /* report back that using the new backend is not necessary
> >   * to achieve the desired configuration */
> >  ret = 1;
> > diff --git a/tests/qemuxml2argvdata/pages-discard-hugepages.args 
> > b/tests/qemuxml2argvdata/pages-discard-hugepages.args
> > index 2dfacefe4a..d859480c26 100644
> > --- a/tests/qemuxml2argvdata/pages-discard-hugepages.args
> > +++ b/tests/qemuxml2argvdata/pages-discard-hugepages.args
> > @@ -10,10 +10,13 @@ QEMU_AUDIO_DRV=none \
> >  -machine pc,accel=tcg,usb=off,dump-guest-core=off \
> >  -m 1024 \
> >  -smp 2,sockets=2,cores=1,threads=1 \
> > --mem-prealloc \
> > --mem-path /dev/hugepages2M/libvirt/qemu/-1-SomeDummyHugepagesGu \
> > --numa node,nodeid=0,cpus=0,mem=256 \
> > --numa node,nodeid=1,cpus=1,mem=768 \
> > +-object memory-backend-file,id=ram-node0,prealloc=yes,\
> > +mem-path=/dev/hugepages2M/libvirt/qemu/-1-SomeDummyHugepagesGu,size=268435456
> >  \
> > +-numa node,nodeid=0,cpus=0,memdev=ram-node0 \
> > +-object memory-backend-file,id=ram-node1,prealloc=yes,\
> > +mem-path=/dev/hugepages2M/libvirt/qemu/-1-SomeDummyHugepagesGu,\
> > +discard-data=yes,size=805306368 \
> > +-numa node,nodeid=1,cpus=1,memdev=ram-node1 \
> 
> This will break migration. But at the same time, it's very unlikely that
> anybody is using discard without hugepages.

So there is different issue, with this patch guest without any hugepages
will fail to start as the memory file is generated in
/var/lib/libvirt/qemu/ram/libvirt/ and QEMU exits with:

memory.c:2053: memory_region_get_ram_ptr: Assertion `mr->ram_block' failed.

I'm dropping this patch :/.

Pavel

> 
> Michal
> 
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Re: [libvirt] [PATCH v2 20/20] qemu: ensure that memory 'discard' is used if specified in XML

2018-08-10 Thread Michal Privoznik 
On 08/09/2018 02:38 PM, Pavel Hrdina wrote:
> Signed-off-by: Pavel Hrdina 
> ---
>  src/qemu/qemu_command.c|  4 +++-
>  .../pages-discard-hugepages.args   | 11 +++
>  tests/qemuxml2argvdata/pages-discard.args  | 18 ++
>  3 files changed, 24 insertions(+), 9 deletions(-)
> 
> diff --git a/src/qemu/qemu_command.c b/src/qemu/qemu_command.c
> index dbeb3a54f6..a7859feae6 100644
> --- a/src/qemu/qemu_command.c
> +++ b/src/qemu/qemu_command.c
> @@ -3147,6 +3147,7 @@ qemuBuildMemoryBackendProps(virJSONValuePtr 
> *backendProps,
>  return -1;
>  
>  if (useHugepage || mem->nvdimmPath || memAccess ||
> +discard == VIR_TRISTATE_BOOL_YES ||
>  def->mem.source == VIR_DOMAIN_MEMORY_SOURCE_FILE) {
>  
>  if (useHugepage) {
> @@ -3228,7 +3229,8 @@ qemuBuildMemoryBackendProps(virJSONValuePtr 
> *backendProps,
>  if (!needHugepage && !mem->sourceNodes && !nodeSpecified &&
>  !mem->nvdimmPath &&
>  memAccess == VIR_DOMAIN_MEMORY_ACCESS_DEFAULT &&
> -def->mem.source != VIR_DOMAIN_MEMORY_SOURCE_FILE && !force) {
> +def->mem.source != VIR_DOMAIN_MEMORY_SOURCE_FILE && !force &&
> +discard != VIR_TRISTATE_BOOL_YES) {
>  /* report back that using the new backend is not necessary
>   * to achieve the desired configuration */
>  ret = 1;
> diff --git a/tests/qemuxml2argvdata/pages-discard-hugepages.args 
> b/tests/qemuxml2argvdata/pages-discard-hugepages.args
> index 2dfacefe4a..d859480c26 100644
> --- a/tests/qemuxml2argvdata/pages-discard-hugepages.args
> +++ b/tests/qemuxml2argvdata/pages-discard-hugepages.args
> @@ -10,10 +10,13 @@ QEMU_AUDIO_DRV=none \
>  -machine pc,accel=tcg,usb=off,dump-guest-core=off \
>  -m 1024 \
>  -smp 2,sockets=2,cores=1,threads=1 \
> --mem-prealloc \
> --mem-path /dev/hugepages2M/libvirt/qemu/-1-SomeDummyHugepagesGu \
> --numa node,nodeid=0,cpus=0,mem=256 \
> --numa node,nodeid=1,cpus=1,mem=768 \
> +-object memory-backend-file,id=ram-node0,prealloc=yes,\
> +mem-path=/dev/hugepages2M/libvirt/qemu/-1-SomeDummyHugepagesGu,size=268435456
>  \
> +-numa node,nodeid=0,cpus=0,memdev=ram-node0 \
> +-object memory-backend-file,id=ram-node1,prealloc=yes,\
> +mem-path=/dev/hugepages2M/libvirt/qemu/-1-SomeDummyHugepagesGu,\
> +discard-data=yes,size=805306368 \
> +-numa node,nodeid=1,cpus=1,memdev=ram-node1 \

This will break migration. But at the same time, it's very unlikely that
anybody is using discard without hugepages.

Michal

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[libvirt] [PATCH v2 20/20] qemu: ensure that memory 'discard' is used if specified in XML

2018-08-09 Thread Pavel Hrdina 
Signed-off-by: Pavel Hrdina 
---
 src/qemu/qemu_command.c|  4 +++-
 .../pages-discard-hugepages.args   | 11 +++
 tests/qemuxml2argvdata/pages-discard.args  | 18 ++
 3 files changed, 24 insertions(+), 9 deletions(-)

diff --git a/src/qemu/qemu_command.c b/src/qemu/qemu_command.c
index dbeb3a54f6..a7859feae6 100644
--- a/src/qemu/qemu_command.c
+++ b/src/qemu/qemu_command.c
@@ -3147,6 +3147,7 @@ qemuBuildMemoryBackendProps(virJSONValuePtr *backendProps,
 return -1;
 
 if (useHugepage || mem->nvdimmPath || memAccess ||
+discard == VIR_TRISTATE_BOOL_YES ||
 def->mem.source == VIR_DOMAIN_MEMORY_SOURCE_FILE) {
 
 if (useHugepage) {
@@ -3228,7 +3229,8 @@ qemuBuildMemoryBackendProps(virJSONValuePtr *backendProps,
 if (!needHugepage && !mem->sourceNodes && !nodeSpecified &&
 !mem->nvdimmPath &&
 memAccess == VIR_DOMAIN_MEMORY_ACCESS_DEFAULT &&
-def->mem.source != VIR_DOMAIN_MEMORY_SOURCE_FILE && !force) {
+def->mem.source != VIR_DOMAIN_MEMORY_SOURCE_FILE && !force &&
+discard != VIR_TRISTATE_BOOL_YES) {
 /* report back that using the new backend is not necessary
  * to achieve the desired configuration */
 ret = 1;
diff --git a/tests/qemuxml2argvdata/pages-discard-hugepages.args 
b/tests/qemuxml2argvdata/pages-discard-hugepages.args
index 2dfacefe4a..d859480c26 100644
--- a/tests/qemuxml2argvdata/pages-discard-hugepages.args
+++ b/tests/qemuxml2argvdata/pages-discard-hugepages.args
@@ -10,10 +10,13 @@ QEMU_AUDIO_DRV=none \
 -machine pc,accel=tcg,usb=off,dump-guest-core=off \
 -m 1024 \
 -smp 2,sockets=2,cores=1,threads=1 \
--mem-prealloc \
--mem-path /dev/hugepages2M/libvirt/qemu/-1-SomeDummyHugepagesGu \
--numa node,nodeid=0,cpus=0,mem=256 \
--numa node,nodeid=1,cpus=1,mem=768 \
+-object memory-backend-file,id=ram-node0,prealloc=yes,\
+mem-path=/dev/hugepages2M/libvirt/qemu/-1-SomeDummyHugepagesGu,size=268435456 \
+-numa node,nodeid=0,cpus=0,memdev=ram-node0 \
+-object memory-backend-file,id=ram-node1,prealloc=yes,\
+mem-path=/dev/hugepages2M/libvirt/qemu/-1-SomeDummyHugepagesGu,\
+discard-data=yes,size=805306368 \
+-numa node,nodeid=1,cpus=1,memdev=ram-node1 \
 -uuid ef1bdff4-27f3-4e85-a807-5fb4d58463cc \
 -display none \
 -no-user-config \
diff --git a/tests/qemuxml2argvdata/pages-discard.args 
b/tests/qemuxml2argvdata/pages-discard.args
index 9db8c72a22..4ae20f531f 100644
--- a/tests/qemuxml2argvdata/pages-discard.args
+++ b/tests/qemuxml2argvdata/pages-discard.args
@@ -10,10 +10,20 @@ QEMU_AUDIO_DRV=none \
 -machine pc,accel=tcg,usb=off,dump-guest-core=off \
 -m 4096 \
 -smp 4,sockets=4,cores=1,threads=1 \
--numa node,nodeid=0,cpus=0,mem=1024 \
--numa node,nodeid=1,cpus=1,mem=1024 \
--numa node,nodeid=2,cpus=2,mem=1024 \
--numa node,nodeid=3,cpus=3,mem=1024 \
+-object memory-backend-file,id=ram-node0,\
+mem-path=/var/lib/libvirt/qemu/ram/libvirt/qemu/-1-QEMUGuest1/ram-node0,\
+discard-data=yes,size=1073741824 \
+-numa node,nodeid=0,cpus=0,memdev=ram-node0 \
+-object memory-backend-ram,id=ram-node1,size=1073741824 \
+-numa node,nodeid=1,cpus=1,memdev=ram-node1 \
+-object memory-backend-file,id=ram-node2,\
+mem-path=/var/lib/libvirt/qemu/ram/libvirt/qemu/-1-QEMUGuest1/ram-node2,\
+discard-data=yes,size=1073741824 \
+-numa node,nodeid=2,cpus=2,memdev=ram-node2 \
+-object memory-backend-file,id=ram-node3,\
+mem-path=/var/lib/libvirt/qemu/ram/libvirt/qemu/-1-QEMUGuest1/ram-node3,\
+discard-data=yes,size=1073741824 \
+-numa node,nodeid=3,cpus=3,memdev=ram-node3 \
 -uuid c7a5fdbd-edaf-9455-926a-d65c16db1809 \
 -display none \
 -no-user-config \
-- 
2.17.1

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