similar to: vram_dirty vs. shadow paging dirty tracking

The patch deals with the situation which guest OS uses unused page table pages as data pages and write data to them. The pages will still be grabbed by Xen as page table pages, and lots of unnecessary page faults occur. The patch will check if the data guest writes to the page table contains valid mfn or not, if not, we believe it is a data page now and then unshadow the page. The patch

We (Michael Fetterman, George Dunlap and I) have been working over the last while on a full replacement for Xen''s shadow pagetable support. This mail contains some design notes, below; a patch against xen-unstable, giving a snapshot of the current state of the new shadow code, is at http://www.cl.cam.ac.uk/~tjd21/shadow2.patch Comments on both are welcome, although the code is not

Dear All: I am pretty new to xen-devel, please correct me in the following. Assume we have the following terms GPT: guest page table SPT: shadow page table (Question a) When guest OS is running, is it always using SPT for address translation? If it is the case, how does guest OS refer and modify its own GPT content? It seems that there is a page table entry in SPT for the GPT page. (Question

Hello, I''m new to Xen and especially to the hypervisor code. I''m working off a 3.0.4.1 base and have the following questions regarding the memory management code for an x86, 32-bit platform (capable of supporting PAE). I''m doing some research into providing grant table hypercall support from a Windows 2003 HVM. I have made all the necessary changes to allow the

(moving to xen-devel, xen-arm is for the older PV ARM port) On Tue, 2013-06-25 at 23:59 +0000, Eric Trudeau wrote: > Hi, I am trying to build the XEN tools for our port of XEN to our > Cortex A15-based platform. > > I am using the repo at git://xenbits.xenproject.org/xen.git to > cross-compile the tools into our rootfs. Which branch/changeset are you using? I've heard that

The following two patches allow the parallel use of memsharing, xenpaging and xen-access by using an independent ring buffer for each feature. Please review. v2: - update mem_event_check_ring arguments, check domain rather than domain_id - check ring_full first because its value was just evaluated - check if ring buffer is initialized before calling mem_access_domctl/mem_paging_domctl

The following two patches are about how to speed up in xenpaging when page in pages. On suse11-64 with 4G memory,if we page out 2G pages,it will cost about 15.5 seconds, but take 2088 seconds to finish paging in.If page-in costs too much time,it will cause unmesurable problems when vm or dom0 access the paged_out page,such as BSOD,crash. What鈥檚 more,the dom0 is always in high I/O pressure.

ging_prep ensures that an mfn is backing the paged-out gfn, and transitions to the next state in the paging state machine for this page. Foreign mappings of the gfn will now succeed. This is the key idea, as it allows the pager to now map the gfn and fill in its contents. Unfortunately, it also allows any other foreign mapper to map the gfn and read its contents. This is particularly dangerous

Hello, Recently many advanced memory mechanisms are introduced into Xen. One problem we found is the conflict between p2m query and setting. For example, backend drivers always map domU’s page to its own space, during the mapping procedure, situations as follow may happen, when mfn is obtained by gfn_to_mfn(), this mfn is likely to be paged out. first case: grant mapping

The patch ''mem_event: use wait queue when ring is full'' I just sent out makes use of the waitqueue feature. There are two issues I get with the change applied: I think I got the logic right, and in my testing vcpu->pause_count drops to zero in p2m_mem_paging_resume(). But for some reason the vcpu does not make progress after the first wakeup. In my debugging there is one

There are BIOSes that want to map the IO-APIC MMIO region from some ACPI method(s), and there is at least one BIOS flavor that wants to use this mapping to clear an RTE''s mask bit. While we can''t allow the latter, we can permit reads and simply drop write attempts, leveraging the already existing infrastructure introduced for dealing with AMD IOMMUs'' representation as

Hi Jan, It seems the last changes to xen-unstable to implement multi-msi-irq''s cause some trouble. The guest starts and works fine. But it causes a xen crash when shutting the guest down. (xen_changeset: Thu Jul 4 16:01:06 2013 +0100 git:d4435fe) If you need more info than given below in the serial log snippet, just say so .. -- Sander (XEN) [2013-07-17 19:10:09] AMD-Vi: Share p2m

Populate-on-demand: Check pages being returned by the balloon driver This patch series is the second result of my work last summer on decreasing fragmentation of superpages in a guests'' p2m when using populate-on-demand. This patch series is against 4.1; I''m posting it to get feedback on the viability of getting a ported version of this patch into 4.2. As with the previous

# HG changeset patch # User hongkaixing<hongkaixing@huawei.com> # Date 1325149704 -28800 # Node ID 052727b8165ce6e05002184ae894096214c8b537 # Parent 54a5e994a241a506900ee0e197bb42e5f1d8e759 xenpaging:add a new array to speed up page-in in xenpaging This patch adds a new array named page_out_index to reserve the victim''s index. When page in a page,it has to go through a for loop

Hi, Olaf we have tested the xenpaging feature and found some problems. (1) the test case like this : when we start a VM with POD enable, the xenpaging is started at the same time. this case will cause many problems ,finally, we fixed the BUG, the patch is attached below. (2) there is a very serious problem. we have observed many VM crash examples, the error code is not always the same.

On 11/25/2016 05:17 PM, Peter Zijlstra wrote: > On Fri, Nov 25, 2016 at 04:10:04PM +0000, Mark Rutland wrote: >> On Fri, Nov 25, 2016 at 04:21:39PM +0100, Dmitry Vyukov wrote: > >>> What are use cases for such primitive that won't be OK with "read once >>> _and_ atomically"? >> >> I have none to hand. > > Whatever triggers the

On 11/25/2016 05:17 PM, Peter Zijlstra wrote: > On Fri, Nov 25, 2016 at 04:10:04PM +0000, Mark Rutland wrote: >> On Fri, Nov 25, 2016 at 04:21:39PM +0100, Dmitry Vyukov wrote: > >>> What are use cases for such primitive that won't be OK with "read once >>> _and_ atomically"? >> >> I have none to hand. > > Whatever triggers the

In sh_page_fault(), there are some code like following, why we think it is mmio only when paging_vcpu_mode_translate(v)? Thanks Yunhong Jiang /* What mfn is the guest trying to access? */ gfn = guest_l1e_get_gfn(gw.eff_l1e); gmfn = vcpu_gfn_to_mfn(v, gfn); mmio = (is_hvm_domain(d) && paging_vcpu_mode_translate(v) &&

There has been some progress, but still no joy. Definitely not intended for inclusion at this point. Tim, Wei, I added a Xen command line toggle to disable IOMMU and P2M table sharing. Tim, I verified that changes to p2m-pt.c don''t break shadow mode (64bit hypervisor and Win 7 guest). Hongkaixing, I incorporated your suggestion in patch 2, so I should add your Signed-off-by eventually.

From: Zhang Xiantao <xiantao.zhang@intel.com> With virtual EPT support, L1 hyerpvisor can use EPT hardware for L2 guest''s memory virtualization. In this way, L2 guest''s performance can be improved sharply. According to our testing, some benchmarks can show > 5x performance gain. Signed-off-by: Zhang Xiantao <xiantao.zhang@intel.com> Zhang Xiantao (11):