lwn.git/arch/x86/include/asm/xen/hypercall.h, branch standardize-docs

x86/xen: allow userspace access during hypercalls

2017-07-03T11:26:17+00:00

Userspace application can do a hypercall through /dev/xen/privcmd, and some for some hypercalls argument is a pointers to user-provided structure. When SMAP is supported and enabled, hypervisor can't access. So, lets allow it. The same applies to HYPERVISOR_dm_op, where additionally privcmd driver carefully verify buffer addresses. Cc: stable@vger.kernel.org Signed-off-by: Marek Marczykowski-Górecki Reviewed-by: Juergen Gross Signed-off-by: Juergen Gross

xen: fix HYPERVISOR_dm_op() prototype

2017-06-08T17:40:14+00:00

Change the third parameter to be the required struct xen_dm_op_buf * instead of a generic void * (which blindly accepts any pointer). Signed-off-by: Sergey Dyasli Reviewed-by: Juergen Gross Reviewed-by: Stefano Stabellini Signed-off-by: Juergen Gross

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

x86/xen: Add stack frame dependency to hypercall inline asm calls

2016-02-24T07:35:41+00:00

If a hypercall is inlined at the beginning of a function, gcc can insert the call instruction before setting up a stack frame, which breaks frame pointer convention if CONFIG_FRAME_POINTER is enabled and can result in a bad stack trace. Force a stack frame to be created if CONFIG_FRAME_POINTER is enabled by listing the stack pointer as an output operand for the hypercall inline asm statements. Signed-off-by: Josh Poimboeuf Reviewed-by: David Vrabel Reviewed-by: Borislav Petkov Cc: Andrew Morton Cc: Andy Lutomirski Cc: Andy Lutomirski Cc: Arnaldo Carvalho de Melo Cc: Bernd Petrovitsch Cc: Boris Ostrovsky Cc: Borislav Petkov Cc: Brian Gerst Cc: Chris J Arges Cc: Denys Vlasenko Cc: H. Peter Anvin Cc: Jiri Slaby Cc: Konrad Rzeszutek Wilk Cc: Linus Torvalds Cc: Michal Marek Cc: Namhyung Kim Cc: Pedro Alves Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: live-patching@vger.kernel.org Link: http://lkml.kernel.org/r/c6face5a46713108bded9c4c103637222abc4528.1453405861.git.jpoimboe@redhat.com Signed-off-by: Ingo Molnar

xen: rename dom0_op to platform_op

2015-12-21T14:40:55+00:00

The dom0_op hypercall has been renamed to platform_op since Xen 3.2, which is ancient, and modern upstream Linux kernels cannot run as dom0 and it anymore anyway. Signed-off-by: Stefano Stabellini Reviewed-by: Boris Ostrovsky

xen: use correct type for HYPERVISOR_memory_op()

2015-09-28T13:48:52+00:00

HYPERVISOR_memory_op() is defined to return an "int" value. This is wrong, as the Xen hypervisor will return "long". The sub-function XENMEM_maximum_reservation returns the maximum number of pages for the current domain. An int will overflow for a domain configured with 8TB of memory or more. Correct this by using the correct type. Signed-off-by: Juergen Gross Signed-off-by: David Vrabel

xen/PMU: Sysfs interface for setting Xen PMU mode

2015-08-20T11:24:26+00:00

Set Xen's PMU mode via /sys/hypervisor/pmu/pmu_mode. Add XENPMU hypercall. Signed-off-by: Boris Ostrovsky Reviewed-by: Konrad Rzeszutek Wilk Signed-off-by: David Vrabel

arm: xen: implement multicall hypercall support.

2014-04-24T12:09:46+00:00

As part of this make the usual change to xen_ulong_t in place of unsigned long. This change has no impact on x86. The Linux definition of struct multicall_entry.result differs from the Xen definition, I think for good reasons, and used a long rather than an unsigned long. Therefore introduce a xen_long_t, which is a long on x86 architectures and a signed 64-bit integer on ARM. Use uint32_t nr_calls on x86 for consistency with the ARM definition. Build tested on amd64 and i386 builds. Runtime tested on ARM. Signed-off-by: Ian Campbell Cc: Stefano Stabellini Cc: Konrad Rzeszutek Wilk Cc: Boris Ostrovsky Signed-off-by: David Vrabel

xen-pciback: notify hypervisor about devices intended to be assigned to guests

2013-03-22T14:20:55+00:00

For MSI-X capable devices the hypervisor wants to write protect the MSI-X table and PBA, yet it can't assume that resources have been assigned to their final values at device enumeration time. Thus have pciback do that notification, as having the device controlled by it is a prerequisite to assigning the device to guests anyway. This is the kernel part of hypervisor side commit 4245d33 ("x86/MSI: add mechanism to fully protect MSI-X table from PV guest accesses") on the master branch of git://xenbits.xen.org/xen.git. CC: stable@vger.kernel.org Signed-off-by: Jan Beulich Signed-off-by: Konrad Rzeszutek Wilk

xen/hypercall: fix hypercall fallback code for very old hypervisors

2012-11-04T15:40:42+00:00

While copying the argument structures in HYPERVISOR_event_channel_op() and HYPERVISOR_physdev_op() into the local variable is sufficiently safe even if the actual structure is smaller than the container one, copying back eventual output values the same way isn't: This may collide with on-stack variables (particularly "rc") which may change between the first and second memcpy() (i.e. the second memcpy() could discard that change). Move the fallback code into out-of-line functions, and handle all of the operations known by this old a hypervisor individually: Some don't require copying back anything at all, and for the rest use the individual argument structures' sizes rather than the container's. Reported-by: Dan Carpenter Signed-off-by: Jan Beulich [v2: Reduce #define/#undef usage in HYPERVISOR_physdev_op_compat().] [v3: Fix compile errors when modules use said hypercalls] [v4: Add xen_ prefix to the HYPERCALL_..] [v5: Alter the name and only EXPORT_SYMBOL_GPL one of them] Signed-off-by: Konrad Rzeszutek Wilk