similar to: [PATCH v3 1/2] xen: enter/exit lazy_mmu_mode around m2p_override calls

From: Matt Wilson <msw@amazon.com> Commit f62805f1 introduced a bug where lazy MMU mode isn''t exited if a m2p_add/remove_override call fails. Cc: Stefano Stabellini <stefano.stabellini@eu.citrix.com> Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com> Cc: David Vrabel <david.vrabel@citrix.com> Cc: Anthony

(This is a continuation of "[PATCH v9] xen/grant-table: Avoid m2p_override during mapping") The grant mapping API does m2p_override unnecessarily: only gntdev needs it, for blkback and future netback patches it just cause a lock contention, as those pages never go to userspace. Therefore this series does the following: - the bulk of the original function (everything after the mapping

(This is a continuation of "[PATCH v9] xen/grant-table: Avoid m2p_override during mapping") The grant mapping API does m2p_override unnecessarily: only gntdev needs it, for blkback and future netback patches it just cause a lock contention, as those pages never go to userspace. Therefore this series does the following: - the bulk of the original function (everything after the mapping

Hi all, this patch series enables xen-swiotlb on arm and arm64. It has been heavily reworked compared to the previous versions in order to achieve better performances and to address review comments. We are not using dma_mark_clean to ensure coherency anymore. We call the platform implementation of map_page and unmap_page. We assume that dom0 has been mapped 1:1 (physical address == machine

This flag controls the meaning of gnttab_map_grant_ref.host_addr and specifies that the field contains a refernce to the pte entry to be used to perform the mapping. Therefore move the use of this flag to the point at which we actually use a reference to the pte instead of something else, splitting up the usage of the flag in this way is confusing and potentially error prone. The other flags are

On 10/28/19 4:10 PM, Jason Gunthorpe wrote: > @@ -445,17 +438,9 @@ static void gntdev_vma_close(struct vm_area_struct *vma) > struct gntdev_priv *priv = file->private_data; > > pr_debug("gntdev_vma_close %p\n", vma); > - if (use_ptemod) { > - /* It is possible that an mmu notifier could be running > - * concurrently, so take priv->lock to ensure that

Hi Ian/Stefano, So, I''m back to using pfn space from maxphysaddr below. Stefano, you suggested ballooning, but that would be just too slow. There are lot of pages to be mapped, 4k at a time during guest creation, and I am afraid ballooning and hypercalls to populate EPT will be pretty slow. OTOH, there is tons of address space available between max-physaddr and max pfn in dom0. Stefano,

Is pte_offset_map allowed to happen within lazy mmu? I presume not, because you definitely don't want the mapping pte update to be deferred. Or, more specifically, is kunmap_atomic ever allowed within lazy mmu? I'm looking at kpte_clear_flush; I've already got a patch which turns this into a pv_op, along with a Xen implementation. But I think its probably an excess pv_op for a

Is pte_offset_map allowed to happen within lazy mmu? I presume not, because you definitely don't want the mapping pte update to be deferred. Or, more specifically, is kunmap_atomic ever allowed within lazy mmu? I'm looking at kpte_clear_flush; I've already got a patch which turns this into a pv_op, along with a Xen implementation. But I think its probably an excess pv_op for a

Since when we are using the m2p_override it is not true anymore that the mmap''ed area doesn''t have corresponsing struct pages. Removing the VM_PFNMAP flag makes get_user_pages work on the mmap''ed user vma. An example test case would be using a Xen userspace block backend (QDISK) on a file on NFS using O_DIRECT. The patch should be backported back to 2.6.38.

On 27/02/14 15:55, Zoltan Kiss wrote: > (This is a continuation of "[PATCH v9] xen/grant-table: Avoid m2p_override > during mapping") > > The grant mapping API does m2p_override unnecessarily: only gntdev needs it, > for blkback and future netback patches it just cause a lock contention, as > those pages never go to userspace. Therefore this series does the following:

This patch implements persistent grants for the xen-blk{front,back} mechanism. The effect of this change is to reduce the number of unmap operations performed, since they cause a (costly) TLB shootdown. This allows the I/O performance to scale better when a large number of VMs are performing I/O. Previously, the blkfront driver was supplied a bvec[] from the request queue. This was granted to

[ REPOST: Apologies to anyone who has seen this before. It didn't make it onto any of the lists it should have. -J ] Hi Andrew, This series of patches lays the basic ground work for the paravirtualized kernel patches coming later on. I think this lot is ready for the rough-and-tumble world of the -mm tree. For the most part, these patches do nothing or very little. The patches should

[ REPOST: Apologies to anyone who has seen this before. It didn't make it onto any of the lists it should have. -J ] Hi Andrew, This series of patches lays the basic ground work for the paravirtualized kernel patches coming later on. I think this lot is ready for the rough-and-tumble world of the -mm tree. For the most part, these patches do nothing or very little. The patches should

At OLS I gave a talk on some of the Xen scalability inhibitors, and one of these was writable page tables. We went over why the feature does not scale, but just as important, we found that the uniprocessor case does not provide any advantage either. These tests were done on x86_64, so I wanted to run the 1-way test on 32 bit to show the same problem. So, I have run with writable PTs and

This is a cherry pick of two patches that add support for guest paged out frames in the XCP 2.6.32 dom0 patch queue. First patch propagates the ENOENT returned by the hypervisor in the case of a paged out page, all the way up the call chain to the MMAPBATCH_V2 ioctl. The ioctl is mainly used to harvest those return values and retry. The second patch adds retry loops to all backend grant

Patrick, there following patches fix xenpaging for me. Granttable handling is incomplete. If a page is gone, a GNTST_eagain should be returned to the caller to inidcate the hypercall has to be retried after a while, until the page is available again. Please review. Olaf _______________________________________________ Xen-devel mailing list Xen-devel@lists.xensource.com

Hey, Linus released this Saturday v3.5 and there were quite a few of interesting components/fixes/features that went in! Going to go down the list of what shortlog provided: - Less MSR traps when using AMD machines - so better performance. [andre] - The APIC IPI interface works - which means that ''perf'' in the initial domain works. So no more lockups. Also with some

Today paravirtualization is a all-or-nothing game: either a kernel is compiled with no paravirtualization support at all, or it is supporting paravirtualized environments like Xen pv-guests or lguest additionally to some paravirtualized tuning for KVM, Hyperv, VMWare or Xen HVM-guests. As support of pv-guests requires quite intrusive pv-hooks (e.g. all access functions to page table entries,

Today paravirtualization is a all-or-nothing game: either a kernel is compiled with no paravirtualization support at all, or it is supporting paravirtualized environments like Xen pv-guests or lguest additionally to some paravirtualized tuning for KVM, Hyperv, VMWare or Xen HVM-guests. As support of pv-guests requires quite intrusive pv-hooks (e.g. all access functions to page table entries,