On Thu, Oct 02, 2014 at 07:06:40PM +0200, Alexander Graf wrote:
I think we're best off to keep the user space API native endian. So
really we should only ever have to convert from big to native endian on
read and native to big on write.
With that QEMU should do the right thing already, no?
2014-10-03 00:30+0300, Nadav Amit:
KVM does not deliver x2APIC broadcast messages with physical mode. Intel SDM
(10.12.9 ICR Operation in x2APIC Mode) states: A destination ID value of
_H is used for broadcast of interrupts in both logical destination and
physical destination modes.
2014-10-02 17:52+0300, Nadav Amit:
2014-09-30 20:49+0300, Nadav Amit:
NoBigReal emulation should consider the effective address is between 0 and
0x instead of checking the logical address.
[...]
Please don’t apply this patch (only this one - 3/6).
I observe strange behaviour which
On Wed, Oct 01, 2014 at 11:34:54AM +0100, Anup Patel wrote:
The KVM_EXIT_SYSTEM_EVENT exit reason was added to define
architecture independent system-wide events for a Guest.
Currently, it is used by in-kernel PSCI-0.2 emulation of
KVM ARM/ARM64 to inform user space about PSCI SYSTEM_OFF
or
On Wed, Oct 01, 2014 at 11:34:51AM +0100, Anup Patel wrote:
This patchset updates KVMTOOL to use some of the features
supported by Linux-3.16 KVM ARM/ARM64, such as:
1. Target CPU == Host using KVM_ARM_PREFERRED_TARGET vm ioctl
2. Target CPU type Potenza for using KVMTOOL on X-Gene
3. PSCI
Provide a new swapfile method for remap_anon_pages to verify the swap
entry is mapped only in one vma before relocating the swap entry in a
different virtual address. Otherwise if the swap entry is mapped
in multiple vmas, when the page is swapped back in, it could get
mapped in a non linear way
Add the syscall numbers.
Signed-off-by: Andrea Arcangeli aarca...@redhat.com
---
arch/powerpc/include/asm/systbl.h | 2 ++
arch/powerpc/include/asm/unistd.h | 2 +-
arch/powerpc/include/uapi/asm/unistd.h | 2 ++
3 files changed, 5 insertions(+), 1 deletion(-)
diff --git
It is generally inefficient to ask the wakeup of userfault ranges
where there's not a single userfault address read through
userfaultfd_read earlier and in turn waiting a wakeup. However it may
come handy to wakeup the same userfault range twice in case of
multiple thread faulting on the same
Userfaultfd needs to wake all waitqueues (pass 0 as nr parameter),
instead of the current hardcoded 1 (that would wake just the first
waitqueue in the head list).
Signed-off-by: Andrea Arcangeli aarca...@redhat.com
---
include/linux/wait.h | 5 +++--
kernel/sched/wait.c | 7 ---
Signed-off-by: Andrea Arcangeli aarca...@redhat.com
---
arch/mips/mm/gup.c | 8 +++-
arch/powerpc/mm/gup.c| 6 ++
arch/s390/kvm/kvm-s390.c | 4 +---
arch/s390/mm/gup.c | 6 ++
arch/sh/mm/gup.c | 6 ++
arch/sparc/mm/gup.c | 6 ++
arch/x86/mm/gup.c
Once an userfaultfd is created MADV_USERFAULT regions talks through
the userfaultfd protocol with the thread responsible for doing the
memory externalization of the process.
The protocol starts by userland writing the requested/preferred
USERFAULT_PROTOCOL version into the userfault fd (64bit
From: Andres Lagar-Cavilla andre...@google.com
Reviewed-by: Radim Krčmář rkrc...@redhat.com
Signed-off-by: Andres Lagar-Cavilla andre...@google.com
Signed-off-by: Andrea Arcangeli aarca...@redhat.com
---
include/linux/mm.h | 1 +
mm/gup.c | 4
2 files changed, 5 insertions(+)
From: Andres Lagar-Cavilla andre...@google.com
When KVM handles a tdp fault it uses FOLL_NOWAIT. If the guest memory
has been swapped out or is behind a filemap, this will trigger async
readahead and return immediately. The rationale is that KVM will kick
back the guest with an async page fault
This teaches gup_fast and __gup_fast to re-enable irqs and
cond_resched() if possible every BATCH_PAGES.
This must be implemented by other archs as well and it's a requirement
before converting more get_user_pages() to get_user_pages_fast() as an
optimization (instead of using
Hello everyone,
There's a large To/Cc list for this RFC because this adds two new
syscalls (userfaultfd and remap_anon_pages) and
MADV_USERFAULT/MADV_NOUSERFAULT, so suggestions on changes are welcome
sooner than later.
The major change compared to the previous RFC I sent a few months ago
is
Those two helpers are needed by remap_anon_pages.
Signed-off-by: Andrea Arcangeli aarca...@redhat.com
---
include/linux/mm.h | 4
mm/fremap.c| 29 +
2 files changed, 33 insertions(+)
diff --git a/include/linux/mm.h b/include/linux/mm.h
index
We run out of 32bits in vm_flags, noop change for 64bit archs.
Signed-off-by: Andrea Arcangeli aarca...@redhat.com
---
fs/proc/task_mmu.c | 4 ++--
include/linux/huge_mm.h | 4 ++--
include/linux/ksm.h | 4 ++--
include/linux/mm_types.h | 2 +-
mm/huge_memory.c | 2 +-
Hello all,
I am new to KVM and look at a particular case in KVM.
I know that KVM uses CFS.
The question I have is as follows:
- I have two VMs with 2 VCPU each. And the actual
CPUs are also 2 and both the VMs use the 2 CPUs.
I want one VM to use only 25 % of the actual CPU and the
remaining
Erik Rull wrote:
On September 12, 2014 at 7:29 PM Jan Kiszka jan.kis...@siemens.com wrote:
On 2014-09-12 19:15, Jan Kiszka wrote:
On 2014-09-12 14:29, Erik Rull wrote:
On September 11, 2014 at 3:32 PM Jan Kiszka jan.kis...@siemens.com
wrote:
On 2014-09-11 15:25, Erik Rull wrote:
On August
remap_anon_pages (unlike remap_file_pages) tries to be non intrusive
in the rmap code.
As far as the rmap code is concerned, rmap_anon_pages only alters the
page-mapping and page-index. It does it while holding the page
lock. However there are a few places that in presence of anon pages
are
Just an optimization.
Signed-off-by: Andrea Arcangeli aarca...@redhat.com
---
drivers/dma/iovlock.c | 10 ++
drivers/iommu/amd_iommu_v2.c | 6 ++
drivers/media/pci/ivtv/ivtv-udma.c | 6 ++
drivers/scsi/st.c | 10 ++
We can leverage the VM_FAULT_RETRY functionality in the page fault
paths better by using either get_user_pages_locked or
get_user_pages_unlocked.
The former allow conversion of get_user_pages invocations that will
have to pass a locked parameter to know if the mmap_sem was dropped
during the
This adds two protocol commands to the userfaultfd protocol.
To register memory regions into userfaultfd you can write 16 bytes as:
[ start|0x1, end ]
to unregister write:
[ start|0x2, end ]
End is start+len (not start+len-1). Same as vma-vm_end.
This also enforces the
This new syscall will move anon pages across vmas, atomically and
without touching the vmas.
It only works on non shared anonymous pages because those can be
relocated without generating non linear anon_vmas in the rmap code.
It is the ideal mechanism to handle userspace page faults. Normally
This needs more explanation than that one-liner comment. Make the
commit message explain why the new FOLL_TRIED flag exists.
Linus
On Fri, Oct 3, 2014 at 10:07 AM, Andrea Arcangeli aarca...@redhat.com wrote:
From: Andres Lagar-Cavilla andre...@google.com
Reviewed-by: Radim Krčmář
MADV_USERFAULT is a new madvise flag that will set VM_USERFAULT in the
vma flags. Whenever VM_USERFAULT is set in an anonymous vma, if
userland touches a still unmapped virtual address, a sigbus signal is
sent instead of allocating a new page. The sigbus signal handler will
then resolve the page
On Fri, Oct 3, 2014 at 10:07 AM, Andrea Arcangeli aarca...@redhat.com wrote:
This teaches gup_fast and __gup_fast to re-enable irqs and
cond_resched() if possible every BATCH_PAGES.
This is disgusting.
Many (most?) __gup_fast() users just want a single page, and the
stupid overhead of the
On Fri, Oct 3, 2014 at 10:08 AM, Andrea Arcangeli aarca...@redhat.com wrote:
Overall this looks a fairly small change to the rmap code, notably
less intrusive than the nonlinear vmas created by remap_file_pages.
Considering that remap_file_pages() was an unmitigated disaster, and
-mm has a
KVM never supported the CPUID_ACPI flag, so it doesn't make sense to
have it enabled by default when KVM is enabled.
The motivation here is exactly the same we had for the MONITOR flag
(disabled by commit 136a7e9a85d7047461f8153f7d12c514a3d68f69).
And like on the MONITOR flag case, we don't need
Changes v2 - v3:
* None. This is just a rebase against latest qemu.git master (commit b00a0dd)
Changes v1 - v2:
* Commit message and comment changes.
* Update compat code to change pc-*-2.1, not pc-*-2.0.
* Added patch to disable SVM by default in KVM mode.
Most of the bits that make enforce
We will need new compat code for the 2.1 machine-types.
Signed-off-by: Eduardo Habkost ehabk...@redhat.com
---
hw/i386/pc_piix.c | 13 -
hw/i386/pc_q35.c | 13 -
2 files changed, 24 insertions(+), 2 deletions(-)
diff --git a/hw/i386/pc_piix.c b/hw/i386/pc_piix.c
index
The x86_cpu_compat_disable_kvm_features() name was a bit confusing, as
it won't forcibly disable the feature for all CPU models (i.e. add it to
kvm_default_unset_features), but it will instead turn off the KVM
auto-enabling of the feature (i.e. remove it from kvm_default_features),
meaning the
The following CPU features were never supported by neither TCG or KVM,
so they are useless on the CPU model definitions, today:
* CPUID_DTS (DS)
* CPUID_HT
* CPUID_TM
* CPUID_PBE
* CPUID_EXT_DTES64
* CPUID_EXT_DSCPL
* CPUID_EXT_EST
* CPUID_EXT_TM2
* CPUID_EXT_XTPR
* CPUID_EXT_PDCM
*
TCG doesn't support VMX, and nested VMX is not enabled by default on the
KVM kernel module.
So, there's no reason to have VMX enabled by default on the core2duo and
coreduo CPU models, today. Even the newer Intel CPU model definitions
don't have it enabled.
In this case, we need machine-type
Make SVM be disabled by default on all CPU models when in KVM mode.
Nested SVM is enabled by default in the KVM kernel module, but it is
probably less stable than nested VMX (which is already disabled by
default).
Add a new compat function, x86_cpu_compat_kvm_no_autodisable(), to keep
This needs more explanation than that one-liner comment. Make the
commit message explain why the new FOLL_TRIED flag exists.
This patch actually is extracted from a 3.18 commit in the KVM tree,
https://git.kernel.org/cgit/virt/kvm/kvm.git/commit/?h=nextid=234b239b.
Here is how that patch uses
Am 03.10.2014 um 14:05 schrieb Paul Mackerras pau...@samba.org:
On Thu, Oct 02, 2014 at 07:06:40PM +0200, Alexander Graf wrote:
I think we're best off to keep the user space API native endian. So
really we should only ever have to convert from big to native endian on
read and native to
Il 03/10/2014 21:39, Eduardo Habkost ha scritto:
Changes v2 - v3:
* None. This is just a rebase against latest qemu.git master (commit b00a0dd)
Changes v1 - v2:
* Commit message and comment changes.
* Update compat code to change pc-*-2.1, not pc-*-2.0.
* Added patch to disable SVM by
On Fri, Oct 03, 2014 at 07:07:58PM +0200, Andrea Arcangeli wrote:
MADV_USERFAULT is a new madvise flag that will set VM_USERFAULT in the
vma flags. Whenever VM_USERFAULT is set in an anonymous vma, if
userland touches a still unmapped virtual address, a sigbus signal is
sent instead of
Hi,
I've been regularly seeing on the 3.10 stable kernels the same problem
as reported by Romain Francoise here:
https://lkml.org/lkml/2013/1/23/492
An example from my setup is at the bottom of this mail. It's a problem
as qemu fails to run when it hits this, only solution is to do all qemu
-BEGIN PGP SIGNED MESSAGE-
Hash: SHA1
On 10/04/2014 07:05 AM, Alexander Graf wrote:
Am 03.10.2014 um 14:05 schrieb Paul Mackerras pau...@samba.org:
On Thu, Oct 02, 2014 at 07:06:40PM +0200, Alexander Graf wrote:
I think we're best off to keep the user space API native endian.
On Thu, Oct 02, 2014 at 07:06:40PM +0200, Alexander Graf wrote:
I think we're best off to keep the user space API native endian. So
really we should only ever have to convert from big to native endian on
read and native to big on write.
With that QEMU should do the right thing already, no?
Am 03.10.2014 um 14:05 schrieb Paul Mackerras pau...@samba.org:
On Thu, Oct 02, 2014 at 07:06:40PM +0200, Alexander Graf wrote:
I think we're best off to keep the user space API native endian. So
really we should only ever have to convert from big to native endian on
read and native to
-BEGIN PGP SIGNED MESSAGE-
Hash: SHA1
On 10/04/2014 07:05 AM, Alexander Graf wrote:
Am 03.10.2014 um 14:05 schrieb Paul Mackerras pau...@samba.org:
On Thu, Oct 02, 2014 at 07:06:40PM +0200, Alexander Graf wrote:
I think we're best off to keep the user space API native endian.
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