kernel/linux.git/drivers/xen/privcmd.c, branch linux-4.16.y

xen/privcmd: remove unused variable pageidx

2017-11-08T14:15:28+00:00

Variable pageidx is assigned a value but it is never read, hence it is redundant and can be removed. Cleans up clang warning: drivers/xen/privcmd.c:199:2: warning: Value stored to 'pageidx' is never read Signed-off-by: Colin Ian King Reviewed-by: Juergen Gross Signed-off-by: Boris Ostrovsky

xen/privcmd: Support correctly 64KB page granularity when mapping memory

2017-06-07T09:23:14+00:00

Commit 5995a68 "xen/privcmd: Add support for Linux 64KB page granularity" did not go far enough to support 64KB in mmap_batch_fn. The variable 'nr' is the number of 4KB chunk to map. However, when Linux is using 64KB page granularity the array of pages (vma->vm_private_data) contain one page per 64KB. Fix it by incrementing st->index correctly. Furthermore, st->va is not correctly incremented as PAGE_SIZE != XEN_PAGE_SIZE. Fixes: 5995a68 ("xen/privcmd: Add support for Linux 64KB page granularity") CC: stable@vger.kernel.org Reported-by: Feng Kan Signed-off-by: Julien Grall Reviewed-by: Boris Ostrovsky Signed-off-by: Juergen Gross

mm, fs: reduce fault, page_mkwrite, and pfn_mkwrite to take only vmf

2017-02-25T01:46:54+00:00

->fault(), ->page_mkwrite(), and ->pfn_mkwrite() calls do not need to take a vma and vmf parameter when the vma already resides in vmf. Remove the vma parameter to simplify things. [arnd@arndb.de: fix ARM build] Link: http://lkml.kernel.org/r/20170125223558.1451224-1-arnd@arndb.de Link: http://lkml.kernel.org/r/148521301778.19116.10840599906674778980.stgit@djiang5-desk3.ch.intel.com Signed-off-by: Dave Jiang Signed-off-by: Arnd Bergmann Reviewed-by: Ross Zwisler Cc: Theodore Ts'o Cc: Darrick J. Wong Cc: Matthew Wilcox Cc: Dave Hansen Cc: Christoph Hellwig Cc: Jan Kara Cc: Dan Williams Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

xen/privcmd: add IOCTL_PRIVCMD_RESTRICT

2017-02-14T20:14:59+00:00

The purpose if this ioctl is to allow a user of privcmd to restrict its operation such that it will no longer service arbitrary hypercalls via IOCTL_PRIVCMD_HYPERCALL, and will check for a matching domid when servicing IOCTL_PRIVCMD_DM_OP or IOCTL_PRIVCMD_MMAP*. The aim of this is to limit the attack surface for a compromised device model. Signed-off-by: Paul Durrant Signed-off-by: Boris Ostrovsky

xen/privcmd: Add IOCTL_PRIVCMD_DM_OP

2017-02-14T20:13:43+00:00

Recently a new dm_op[1] hypercall was added to Xen to provide a mechanism for restricting device emulators (such as QEMU) to a limited set of hypervisor operations, and being able to audit those operations in the kernel of the domain in which they run. This patch adds IOCTL_PRIVCMD_DM_OP as gateway for __HYPERVISOR_dm_op. NOTE: There is no requirement for user-space code to bounce data through locked memory buffers (as with IOCTL_PRIVCMD_HYPERCALL) since privcmd has enough information to lock the original buffers directly. [1] http://xenbits.xen.org/gitweb/?p=xen.git;a=commit;h=524a98c2 Signed-off-by: Paul Durrant Acked-by: Stefano Stabellini Signed-off-by: Boris Ostrovsky

xen/privcmd: return -ENOTTY for unimplemented IOCTLs

2017-02-13T18:49:00+00:00

The code sets the default return code to -ENOSYS but then overrides this to -EINVAL in the switch() statement's default case, which is clearly silly. This patch removes the override and sets the default return code to -ENOTTY, which is the conventional return for an unimplemented ioctl. Signed-off-by: Paul Durrant Signed-off-by: Boris Ostrovsky

mm: use vmf->address instead of of vmf->virtual_address

2016-12-15T00:04:09+00:00

Every single user of vmf->virtual_address typed that entry to unsigned long before doing anything with it so the type of virtual_address does not really provide us any additional safety. Just use masked vmf->address which already has the appropriate type. Link: http://lkml.kernel.org/r/1479460644-25076-3-git-send-email-jack@suse.cz Signed-off-by: Jan Kara Acked-by: Kirill A. Shutemov Cc: Dan Williams Cc: Ross Zwisler Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

xen: use vma_pages().

2016-07-06T09:34:47+00:00

Replace explicit computation of vma page count by a call to vma_pages(). Signed-off-by: Muhammad Falak R Wani Reviewed-by: Boris Ostrovsky Signed-off-by: David Vrabel

xen/privcmd: Add support for Linux 64KB page granularity

2015-10-23T13:20:42+00:00

The hypercall interface (as well as the toolstack) is always using 4KB page granularity. When the toolstack is asking for mapping a series of guest PFN in a batch, it expects to have the page map contiguously in its virtual memory. When Linux is using 64KB page granularity, the privcmd driver will have to map multiple Xen PFN in a single Linux page. Note that this solution works on page granularity which is a multiple of 4KB. Signed-off-by: Julien Grall Reviewed-by: David Vrabel Signed-off-by: David Vrabel

xen/balloon: make alloc_xenballoon_pages() always allocate low pages

2015-10-23T13:20:05+00:00

All users of alloc_xenballoon_pages() wanted low memory pages, so remove the option for high memory. Signed-off-by: David Vrabel Reviewed-by: Daniel Kiper