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*-. Merge branches 'stable/bug.fixes-3.2' and 'stable/mmu.fixes' of ↵Linus Torvalds2011-10-251-19/+109
|\ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen * 'stable/bug.fixes-3.2' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen: xen/p2m/debugfs: Make type_name more obvious. xen/p2m/debugfs: Fix potential pointer exception. xen/enlighten: Fix compile warnings and set cx to known value. xen/xenbus: Remove the unnecessary check. xen/irq: If we fail during msi_capability_init return proper error code. xen/events: Don't check the info for NULL as it is already done. xen/events: BUG() when we can't allocate our event->irq array. * 'stable/mmu.fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen: xen: Fix selfballooning and ensure it doesn't go too far xen/gntdev: Fix sleep-inside-spinlock xen: modify kernel mappings corresponding to granted pages xen: add an "highmem" parameter to alloc_xenballooned_pages xen/p2m: Use SetPagePrivate and its friends for M2P overrides. xen/p2m: Make debug/xen/mmu/p2m visible again. Revert "xen/debug: WARN_ON when identity PFN has no _PAGE_IOMAP flag set."
| | * xen: modify kernel mappings corresponding to granted pagesStefano Stabellini2011-09-291-10/+66
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | If we want to use granted pages for AIO, changing the mappings of a user vma and the corresponding p2m is not enough, we also need to update the kernel mappings accordingly. Currently this is only needed for pages that are created for user usages through /dev/xen/gntdev. As in, pages that have been in use by the kernel and use the P2M will not need this special mapping. However there are no guarantees that in the future the kernel won't start accessing pages through the 1:1 even for internal usage. In order to avoid the complexity of dealing with highmem, we allocated the pages lowmem. We issue a HYPERVISOR_grant_table_op right away in m2p_add_override and we remove the mappings using another HYPERVISOR_grant_table_op in m2p_remove_override. Considering that m2p_add_override and m2p_remove_override are called once per page we use multicalls and hypercall batching. Use the kmap_op pointer directly as argument to do the mapping as it is guaranteed to be present up until the unmapping is done. Before issuing any unmapping multicalls, we need to make sure that the mapping has already being done, because we need the kmap->handle to be set correctly. Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com> [v1: Removed GRANT_FRAME_BIT usage] Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
| | * xen/p2m: Use SetPagePrivate and its friends for M2P overrides.Konrad Rzeszutek Wilk2011-09-231-4/+6
| | | | | | | | | | | | | | | | | | | | | | | | We use the page->private field and hence should use the proper macros and set proper bits. Also WARN_ON in case somebody tries to overwrite our data. Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
| | * xen/p2m: Make debug/xen/mmu/p2m visible again.Konrad Rzeszutek Wilk2011-09-231-3/+32
| |/ |/| | | | | | | | | | | | | | | | | We dropped a lot of the MMU debugfs in favour of using tracing API - but there is one which just provides mostly static information that was made invisible by this change. Bring it back. Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
| * xen/p2m/debugfs: Make type_name more obvious.Konrad Rzeszutek Wilk2011-10-191-2/+5
| | | | | | | | | | | | | | | | | | Per Ian Campbell suggestion to defend against future breakage in case we expand the P2M values, incorporate the defines in the string array. Suggested-by: Ian Campbell <Ian.Campbell@citrix.com> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
| * xen/p2m/debugfs: Fix potential pointer exception.Konrad Rzeszutek Wilk2011-10-191-1/+1
|/ | | | | | | | | We could be referencing the last + 1 element of level_name[] array which would cause a pointer exception, because of the initial setup of lvl=4. [v1: No need to do this for type_name, pointed out by Ian Campbell] Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
*---. Merge branches 'stable/irq', 'stable/p2m.bugfixes', 'stable/e820.bugfixes' ↵Linus Torvalds2011-05-191-2/+28
|\ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | and 'stable/mmu.bugfixes' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen * 'stable/irq' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen: xen: do not clear and mask evtchns in __xen_evtchn_do_upcall * 'stable/p2m.bugfixes' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen: xen/p2m: Create entries in the P2M_MFN trees's to track 1-1 mappings * 'stable/e820.bugfixes' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen: xen/setup: Fix for incorrect xen_extra_mem_start initialization under 32-bit xen/setup: Ignore E820_UNUSABLE when setting 1-1 mappings. * 'stable/mmu.bugfixes' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen: xen mmu: fix a race window causing leave_mm BUG()
| | * | xen/p2m: Create entries in the P2M_MFN trees's to track 1-1 mappingsKonrad Rzeszutek Wilk2011-05-121-2/+28
| |/ / | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | .. when applicable. We need to track in the p2m_mfn and p2m_mfn_p the MFNs and pointers, respectivly, for the P2M entries that are allocated for the identity mappings. Without this, a PV domain with an E820 that triggers the 1-1 mapping to kick in, won't be able to be restored as the P2M won't have the identity mappings. Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
* | | xen/p2m: Add EXPORT_SYMBOL_GPL to the M2P override functions.Konrad Rzeszutek Wilk2011-04-201-1/+2
| | | | | | | | | | | | | | | | | | | | | If the backends, which use these two functions, are compiled as a module we need these two functions to be exported. Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
* | | xen/p2m/m2p/gnttab: Support GNTMAP_host_map in the M2P override.Konrad Rzeszutek Wilk2011-04-181-6/+4
|/ / | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | We only supported the M2P (and P2M) override only for the GNTMAP_contains_pte type mappings. Meaning that we grants operations would "contain the machine address of the PTE to update" If the flag is unset, then the grant operation is "contains a host virtual address". The latter case means that the Hypervisor takes care of updating our page table (specifically the PTE entry) with the guest's MFN. As such we should not try to do anything with the PTE. Previous to this patch we would try to clear the PTE which resulted in Xen hypervisor being upset with us: (XEN) mm.c:1066:d0 Attempt to implicitly unmap a granted PTE c0100000ccc59067 (XEN) domain_crash called from mm.c:1067 (XEN) Domain 0 (vcpu#0) crashed on cpu#3: (XEN) ----[ Xen-4.0-110228 x86_64 debug=y Not tainted ]---- and crashing us. This patch allows us to inhibit the PTE clearing in the PV guest if the GNTMAP_contains_pte is not set. On the m2p_remove_override path we provide the same parameter. Sadly in the grant-table driver we do not have a mechanism to tell m2p_remove_override whether to clear the PTE or not. Since the grant-table driver is used by user-space, we can safely assume that it operates only on PTE's. Hence the implementation for it to work on !GNTMAP_contains_pte returns -EOPNOTSUPP. In the future we can implement the support for this. It will require some extra accounting structure to keep track of the page[i], and the flag. [v1: Added documentation details, made it return -EOPNOTSUPP instead of trying to do a half-way implementation] Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
* | xen: fix p2m section mismatchesRandy Dunlap2011-03-291-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Fix section mismatch warnings: set_phys_range_identity() is called by __init xen_set_identity(), so also mark set_phys_range_identity() as __init. then: __early_alloc_p2m() is called set_phys_range_identity(), so also mark __early_alloc_p2m() as __init. WARNING: arch/x86/built-in.o(.text+0x7856): Section mismatch in reference from the function __early_alloc_p2m() to the function .init.text:extend_brk() The function __early_alloc_p2m() references the function __init extend_brk(). This is often because __early_alloc_p2m lacks a __init annotation or the annotation of extend_brk is wrong. WARNING: arch/x86/built-in.o(.text+0x7967): Section mismatch in reference from the function set_phys_range_identity() to the function .init.text:extend_brk() The function set_phys_range_identity() references the function __init extend_brk(). This is often because set_phys_range_identity lacks a __init annotation or the annotation of extend_brk is wrong. [v2: Per Stephen Hemming recommonedation made __early_alloc_p2m static] Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
* | xen/p2m: Allocate p2m tracking pages on overrideDaniel De Graaf2011-03-241-2/+4
| | | | | | | | | | | | | | | | | | | | It is possible to add a p2m override on pages that are currently mapped to INVALID_P2M_ENTRY; in particular, this will happen when using ballooned pages in gntdev. This means that set_phys_to_machine must be used instead of __set_phys_to_machine. Signed-off-by: Daniel De Graaf <dgdegra@tycho.nsa.gov> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
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*---. \ Merge branches 'stable/ia64', 'stable/blkfront-cleanup' and 'stable/cleanup' ↵Linus Torvalds2011-03-151-3/+3
|\ \ \ \ | | |_|/ | |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen * 'stable/ia64' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen: xen: ia64 build broken due to "xen: switch to new schedop hypercall by default." * 'stable/blkfront-cleanup' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen: xen: Union the blkif_request request specific fields * 'stable/cleanup' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen: xen: annotate functions which only call into __init at start of day xen p2m: annotate variable which appears unused xen: events: mark cpu_evtchn_mask_p as __refdata
| | | * xen: annotate functions which only call into __init at start of dayIan Campbell2011-02-111-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Both xen_hvm_init_shared_info and xen_build_mfn_list_list can be called at resume time as well as at start of day but only reference __init functions (extend_brk) at start of day. Hence annotate with __ref. WARNING: arch/x86/built-in.o(.text+0x4f1): Section mismatch in reference from the function xen_hvm_init_shared_info() to the function .init.text:extend_brk() The function xen_hvm_init_shared_info() references the function __init extend_brk(). This is often because xen_hvm_init_shared_info lacks a __init annotation or the annotation of extend_brk is wrong. xen_hvm_init_shared_info calls extend_brk() iff !shared_info_page and initialises shared_info_page with the result. This happens at start of day only. WARNING: arch/x86/built-in.o(.text+0x599b): Section mismatch in reference from the function xen_build_mfn_list_list() to the function .init.text:extend_brk() The function xen_build_mfn_list_list() references the function __init extend_brk(). This is often because xen_build_mfn_list_list lacks a __init annotation or the annotation of extend_brk is wrong. (this warning occurs multiple times) xen_build_mfn_list_list only calls extend_brk() at boot time, while building the initial mfn list list Signed-off-by: Ian Campbell <ian.campbell@citrix.com> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
| | | * xen p2m: annotate variable which appears unusedIan Campbell2011-02-111-2/+2
| | |/ | |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | CC arch/x86/xen/p2m.o arch/x86/xen/p2m.c: In function 'm2p_remove_override': arch/x86/xen/p2m.c:460: warning: 'address' may be used uninitialized in this function arch/x86/xen/p2m.c: In function 'm2p_add_override': arch/x86/xen/p2m.c:426: warning: 'address' may be used uninitialized in this function In actual fact address is inialised in one "if (!PageHighMem(page))" statement and used in a second and so is always initialised before use. Signed-off-by: Ian Campbell <ian.campbell@citrix.com> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
* | | Merge branches 'stable/p2m-identity.v4.9.1' and 'stable/e820' of ↵Linus Torvalds2011-03-151-7/+317
|\ \ \ | |/ / |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen * 'stable/p2m-identity.v4.9.1' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen: xen/m2p: Check whether the MFN has IDENTITY_FRAME bit set.. xen/m2p: No need to catch exceptions when we know that there is no RAM xen/debug: WARN_ON when identity PFN has no _PAGE_IOMAP flag set. xen/debugfs: Add 'p2m' file for printing out the P2M layout. xen/setup: Set identity mapping for non-RAM E820 and E820 gaps. xen/mmu: WARN_ON when racing to swap middle leaf. xen/mmu: Set _PAGE_IOMAP if PFN is an identity PFN. xen/mmu: Add the notion of identity (1-1) mapping. xen: Mark all initial reserved pages for the balloon as INVALID_P2M_ENTRY. * 'stable/e820' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen: xen/e820: Don't mark balloon memory as E820_UNUSABLE when running as guest and fix overflow. xen/setup: Inhibit resource API from using System RAM E820 gaps as PCI mem gaps.
| * | xen/debugfs: Add 'p2m' file for printing out the P2M layout.Konrad Rzeszutek Wilk2011-03-141-0/+78
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | We walk over the whole P2M tree and construct a simplified view of which PFN regions belong to what level and what type they are. Only enabled if CONFIG_XEN_DEBUG_FS is set. [v2: UNKN->UNKNOWN, use uninitialized_var] [v3: Rebased on top of mmu->p2m code split] [v4: Fixed the else if] Reviewed-by: Ian Campbell <Ian.Campbell@eu.citrix.com> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
| * | xen/mmu: WARN_ON when racing to swap middle leaf.Konrad Rzeszutek Wilk2011-03-141-1/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The initial bootup code uses set_phys_to_machine quite a lot, and after bootup it would be used by the balloon driver. The balloon driver does have mutex lock so this should not be necessary - but just in case, add a WARN_ON if we do hit this scenario. If we do fail this, it is OK to continue as there is a backup mechanism (VM_IO) that can bypass the P2M and still set the _PAGE_IOMAP flags. [v2: Change from WARN to BUG_ON] [v3: Rebased on top of xen->p2m code split] [v4: Change from BUG_ON to WARN] Reviewed-by: Ian Campbell <Ian.Campbell@eu.citrix.com> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
| * | xen/mmu: Add the notion of identity (1-1) mapping.Konrad Rzeszutek Wilk2011-03-141-2/+234
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Our P2M tree structure is a three-level. On the leaf nodes we set the Machine Frame Number (MFN) of the PFN. What this means is that when one does: pfn_to_mfn(pfn), which is used when creating PTE entries, you get the real MFN of the hardware. When Xen sets up a guest it initially populates a array which has descending (or ascending) MFN values, as so: idx: 0, 1, 2 [0x290F, 0x290E, 0x290D, ..] so pfn_to_mfn(2)==0x290D. If you start, restart many guests that list starts looking quite random. We graft this structure on our P2M tree structure and stick in those MFN in the leafs. But for all other leaf entries, or for the top root, or middle one, for which there is a void entry, we assume it is "missing". So pfn_to_mfn(0xc0000)=INVALID_P2M_ENTRY. We add the possibility of setting 1-1 mappings on certain regions, so that: pfn_to_mfn(0xc0000)=0xc0000 The benefit of this is, that we can assume for non-RAM regions (think PCI BARs, or ACPI spaces), we can create mappings easily b/c we get the PFN value to match the MFN. For this to work efficiently we introduce one new page p2m_identity and allocate (via reserved_brk) any other pages we need to cover the sides (1GB or 4MB boundary violations). All entries in p2m_identity are set to INVALID_P2M_ENTRY type (Xen toolstack only recognizes that and MFNs, no other fancy value). On lookup we spot that the entry points to p2m_identity and return the identity value instead of dereferencing and returning INVALID_P2M_ENTRY. If the entry points to an allocated page, we just proceed as before and return the PFN. If the PFN has IDENTITY_FRAME_BIT set we unmask that in appropriate functions (pfn_to_mfn). The reason for having the IDENTITY_FRAME_BIT instead of just returning the PFN is that we could find ourselves where pfn_to_mfn(pfn)==pfn for a non-identity pfn. To protect ourselves against we elect to set (and get) the IDENTITY_FRAME_BIT on all identity mapped PFNs. This simplistic diagram is used to explain the more subtle piece of code. There is also a digram of the P2M at the end that can help. Imagine your E820 looking as so: 1GB 2GB /-------------------+---------\/----\ /----------\ /---+-----\ | System RAM | Sys RAM ||ACPI| | reserved | | Sys RAM | \-------------------+---------/\----/ \----------/ \---+-----/ ^- 1029MB ^- 2001MB [1029MB = 263424 (0x40500), 2001MB = 512256 (0x7D100), 2048MB = 524288 (0x80000)] And dom0_mem=max:3GB,1GB is passed in to the guest, meaning memory past 1GB is actually not present (would have to kick the balloon driver to put it in). When we are told to set the PFNs for identity mapping (see patch: "xen/setup: Set identity mapping for non-RAM E820 and E820 gaps.") we pass in the start of the PFN and the end PFN (263424 and 512256 respectively). The first step is to reserve_brk a top leaf page if the p2m[1] is missing. The top leaf page covers 512^2 of page estate (1GB) and in case the start or end PFN is not aligned on 512^2*PAGE_SIZE (1GB) we loop on aligned 1GB PFNs from start pfn to end pfn. We reserve_brk top leaf pages if they are missing (means they point to p2m_mid_missing). With the E820 example above, 263424 is not 1GB aligned so we allocate a reserve_brk page which will cover the PFNs estate from 0x40000 to 0x80000. Each entry in the allocate page is "missing" (points to p2m_missing). Next stage is to determine if we need to do a more granular boundary check on the 4MB (or 2MB depending on architecture) off the start and end pfn's. We check if the start pfn and end pfn violate that boundary check, and if so reserve_brk a middle (p2m[x][y]) leaf page. This way we have a much finer granularity of setting which PFNs are missing and which ones are identity. In our example 263424 and 512256 both fail the check so we reserve_brk two pages. Populate them with INVALID_P2M_ENTRY (so they both have "missing" values) and assign them to p2m[1][2] and p2m[1][488] respectively. At this point we would at minimum reserve_brk one page, but could be up to three. Each call to set_phys_range_identity has at maximum a three page cost. If we were to query the P2M at this stage, all those entries from start PFN through end PFN (so 1029MB -> 2001MB) would return INVALID_P2M_ENTRY ("missing"). The next step is to walk from the start pfn to the end pfn setting the IDENTITY_FRAME_BIT on each PFN. This is done in 'set_phys_range_identity'. If we find that the middle leaf is pointing to p2m_missing we can swap it over to p2m_identity - this way covering 4MB (or 2MB) PFN space. At this point we do not need to worry about boundary aligment (so no need to reserve_brk a middle page, figure out which PFNs are "missing" and which ones are identity), as that has been done earlier. If we find that the middle leaf is not occupied by p2m_identity or p2m_missing, we dereference that page (which covers 512 PFNs) and set the appropriate PFN with IDENTITY_FRAME_BIT. In our example 263424 and 512256 end up there, and we set from p2m[1][2][256->511] and p2m[1][488][0->256] with IDENTITY_FRAME_BIT set. All other regions that are void (or not filled) either point to p2m_missing (considered missing) or have the default value of INVALID_P2M_ENTRY (also considered missing). In our case, p2m[1][2][0->255] and p2m[1][488][257->511] contain the INVALID_P2M_ENTRY value and are considered "missing." This is what the p2m ends up looking (for the E820 above) with this fabulous drawing: p2m /--------------\ /-----\ | &mfn_list[0],| /-----------------\ | 0 |------>| &mfn_list[1],| /---------------\ | ~0, ~0, .. | |-----| | ..., ~0, ~0 | | ~0, ~0, [x]---+----->| IDENTITY [@256] | | 1 |---\ \--------------/ | [p2m_identity]+\ | IDENTITY [@257] | |-----| \ | [p2m_identity]+\\ | .... | | 2 |--\ \-------------------->| ... | \\ \----------------/ |-----| \ \---------------/ \\ | 3 |\ \ \\ p2m_identity |-----| \ \-------------------->/---------------\ /-----------------\ | .. +->+ | [p2m_identity]+-->| ~0, ~0, ~0, ... | \-----/ / | [p2m_identity]+-->| ..., ~0 | / /---------------\ | .... | \-----------------/ / | IDENTITY[@0] | /-+-[x], ~0, ~0.. | / | IDENTITY[@256]|<----/ \---------------/ / | ~0, ~0, .... | | \---------------/ | p2m_missing p2m_missing /------------------\ /------------\ | [p2m_mid_missing]+---->| ~0, ~0, ~0 | | [p2m_mid_missing]+---->| ..., ~0 | \------------------/ \------------/ where ~0 is INVALID_P2M_ENTRY. IDENTITY is (PFN | IDENTITY_BIT) Reviewed-by: Ian Campbell <ian.campbell@citrix.com> [v5: Changed code to use ranges, added ASCII art] [v6: Rebased on top of xen->p2m code split] [v4: Squished patches in just this one] [v7: Added RESERVE_BRK for potentially allocated pages] [v8: Fixed alignment problem] [v9: Changed 1<<3X to 1<<BITS_PER_LONG-X] [v10: Copied git commit description in the p2m code + Add Review tag] [v11: Title had '2-1' - should be '1-1' mapping] Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
| * | xen: Mark all initial reserved pages for the balloon as INVALID_P2M_ENTRY.Konrad Rzeszutek Wilk2011-03-031-5/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | With this patch, we diligently set regions that will be used by the balloon driver to be INVALID_P2M_ENTRY and under the ownership of the balloon driver. We are OK using the __set_phys_to_machine as we do not expect to be allocating any P2M middle or entries pages. The set_phys_to_machine has the side-effect of potentially allocating new pages and we do not want that at this stage. We can do this because xen_build_mfn_list_list will have already allocated all such pages up to xen_max_p2m_pfn. We also move the check for auto translated physmap down the stack so it is present in __set_phys_to_machine. [v2: Rebased with mmu->p2m code split] Reviewed-by: Ian Campbell <ian.campbell@citrix.com> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
* | | xen/p2m: Mark INVALID_P2M_ENTRY the mfn_list past max_pfn.Stefan Bader2011-01-271-12/+6
|/ / | | | | | | | | | | | | | | | | In case the mfn_list does not have enough entries to fill a p2m page we do not want the entries from max_pfn up to the boundary to be filled with unknown values. Hence set them to INVALID_P2M_ENTRY. Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
* / xen: p2m: correctly initialize partial p2m leafStefan Bader2011-01-211-1/+19
|/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | After changing the p2m mapping to a tree by commit 58e05027b530ff081ecea68e38de8d59db8f87e0 xen: convert p2m to a 3 level tree and trying to boot a DomU with 615MB of memory, the following crash was observed in the dump: kernel direct mapping tables up to 26f00000 @ 1ec4000-1fff000 BUG: unable to handle kernel NULL pointer dereference at (null) IP: [<c0107397>] xen_set_pte+0x27/0x60 *pdpt = 0000000000000000 *pde = 0000000000000000 Adding further debug statements showed that when trying to set up pfn=0x26700 the returned mapping was invalid. pfn=0x266ff calling set_pte(0xc1fe77f8, 0x6b3003) pfn=0x26700 calling set_pte(0xc1fe7800, 0x3) Although the last_pfn obtained from the startup info is 0x26700, which should in turn not be hit, the additional 8MB which are added as extra memory normally seem to be ok. This lead to looking into the initial p2m tree construction, which uses the smaller value and assuming that there is other code handling the extra memory. When the p2m tree is set up, the leaves are directly pointed to the array which the domain builder set up. But if the mapping is not on a boundary that fits into one p2m page, this will result in the last leaf being only partially valid. And as the invalid entries are not initialized in that case, things go badly wrong. I am trying to fix that by checking whether the current leaf is a complete map and if not, allocate a completely new page and copy only the valid pointers there. This may not be the most efficient or elegant solution, but at least it seems to allow me booting DomUs with memory assignments all over the range. BugLink: http://bugs.launchpad.net/bugs/686692 [v2: Redid a bit of commit wording and fixed a compile warning] Signed-off-by: Stefan Bader <stefan.bader@canonical.com> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
* xen/p2m: Fix module linking error.Konrad Rzeszutek Wilk2011-01-111-0/+1
| | | | | | | Fixes: ERROR: "m2p_find_override_pfn" [drivers/block/xen-blkfront.ko] undefined! Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
* xen p2m: clear the old pte when adding a page to m2p_overrideJeremy Fitzhardinge2011-01-111-4/+45
| | | | | | | | | | | | | | | | | When adding a page to m2p_override we change the p2m of the page so we need to also clear the old pte of the kernel linear mapping because it doesn't correspond anymore. When we remove the page from m2p_override we restore the original p2m of the page and we also restore the old pte of the kernel linear mapping. Before changing the p2m mappings in m2p_add_override and m2p_remove_override, check that the page passed as argument is valid and return an error if it is not. Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com> Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
* xen p2m: transparently change the p2m mappings in the m2p overrideStefano Stabellini2011-01-111-0/+12
| | | | | | | | | | In m2p_add_override store the original mfn into page->index and then change the p2m mapping, setting mfns as FOREIGN_FRAME. In m2p_remove_override restore the original mapping. Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
* xen: add m2p override mechanismJeremy Fitzhardinge2011-01-111-0/+80
| | | | | | | | | | | | Add a simple hashtable based mechanism to override some portions of the m2p, so that we can find out the pfn corresponding to an mfn of a granted page. In fact entries corresponding to granted pages in the m2p hold the original pfn value of the page in the source domain that granted it. Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com> Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
* xen: move p2m handling to separate fileJeremy Fitzhardinge2011-01-111-0/+376
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>