Commit Graph

102 Commits

Author SHA1 Message Date
Vitaly Kuznetsov ad5475f9fa x86/xen: use xen_vcpu_id mapping for HYPERVISOR_vcpu_op
HYPERVISOR_vcpu_op() passes Linux's idea of vCPU id as a parameter
while Xen's idea is expected. In some cases these ideas diverge so we
need to do remapping.

Convert all callers of HYPERVISOR_vcpu_op() to use xen_vcpu_nr().

Leave xen_fill_possible_map() and xen_filter_cpu_maps() intact as
they're only being called by PV guests before perpu areas are
initialized. While the issue could be solved by switching to
early_percpu for xen_vcpu_id I think it's not worth it: PV guests will
probably never get to the point where their idea of vCPU id diverges
from Xen's.

Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: David Vrabel <david.vrabel@citrix.com>
2016-07-25 13:32:34 +01:00
Vitaly Kuznetsov 88e957d6e4 xen: introduce xen_vcpu_id mapping
It may happen that Xen's and Linux's ideas of vCPU id diverge. In
particular, when we crash on a secondary vCPU we may want to do kdump
and unlike plain kexec where we do migrate_to_reboot_cpu() we try
booting on the vCPU which crashed. This doesn't work very well for
PVHVM guests as we have a number of hypercalls where we pass vCPU id
as a parameter. These hypercalls either fail or do something
unexpected.

To solve the issue introduce percpu xen_vcpu_id mapping. ARM and PV
guests get direct mapping for now. Boot CPU for PVHVM guest gets its
id from CPUID. With secondary CPUs it is a bit more
trickier. Currently, we initialize IPI vectors before these CPUs boot
so we can't use CPUID. Use ACPI ids from MADT instead.

Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: David Vrabel <david.vrabel@citrix.com>
2016-07-25 13:31:16 +01:00
Juergen Gross 4b5ae0150f arm/xen: add support for vm_assist hypercall
Add support for the Xen HYPERVISOR_vm_assist hypercall.

Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Reviewed-by: Julien Grall <julien.grall@arm.com>
Reviewed-by: Stefano Stabellini <sstabellini@kernel.org>
Signed-off-by: David Vrabel <david.vrabel@citrix.com>
2016-07-06 10:42:14 +01:00
Juergen Gross ecb23dc6f2 xen: add steal_clock support on x86
The pv_time_ops structure contains a function pointer for the
"steal_clock" functionality used only by KVM and Xen on ARM. Xen on x86
uses its own mechanism to account for the "stolen" time a thread wasn't
able to run due to hypervisor scheduling.

Add support in Xen arch independent time handling for this feature by
moving it out of the arm arch into drivers/xen and remove the x86 Xen
hack.

Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Reviewed-by: Stefano Stabellini <sstabellini@kernel.org>
Signed-off-by: David Vrabel <david.vrabel@citrix.com>
2016-07-06 10:34:48 +01:00
Shannon Zhao 0cac5c3018 Xen: EFI: Parse DT parameters for Xen specific UEFI
The EFI DT parameters for bare metal are located under /chosen node,
while for Xen Dom0 they are located under /hyperviosr/uefi node. These
parameters under /chosen and /hyperviosr/uefi are not expected to appear
at the same time.

Parse these EFI parameters and initialize EFI like the way for bare
metal except the runtime services because the runtime services for Xen
Dom0 are available through hypercalls and they are always enabled. So it
sets the EFI_RUNTIME_SERVICES flag if it finds /hyperviosr/uefi node and
bails out in arm_enable_runtime_services() when EFI_RUNTIME_SERVICES
flag is set already.

Signed-off-by: Shannon Zhao <shannon.zhao@linaro.org>
Cc: Stefano Stabellini <sstabellini@kernel.org>
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Leif Lindholm <leif.lindholm@linaro.org>
Signed-off-by: Matt Fleming <matt@codeblueprint.co.uk>
2016-07-06 10:34:47 +01:00
Shannon Zhao be1aaf4e40 ARM64: XEN: Add a function to initialize Xen specific UEFI runtime services
When running on Xen hypervisor, runtime services are supported through
hypercall. Add a Xen specific function to initialize runtime services.

Signed-off-by: Shannon Zhao <shannon.zhao@linaro.org>
Reviewed-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Tested-by: Julien Grall <julien.grall@arm.com>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
2016-07-06 10:34:46 +01:00
Shannon Zhao 9b08aaa319 ARM: XEN: Move xen_early_init() before efi_init()
Move xen_early_init() before efi_init(), then when calling efi_init()
could initialize Xen specific UEFI.

Check if it runs on Xen hypervisor through the flat dts.

Cc: Russell King <linux@arm.linux.org.uk>
Signed-off-by: Shannon Zhao <shannon.zhao@linaro.org>
Reviewed-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Reviewed-by: Julien Grall <julien.grall@arm.com>
Tested-by: Julien Grall <julien.grall@arm.com>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
2016-07-06 10:34:45 +01:00
Shannon Zhao d22cbe651f arm/xen: Get event-channel irq through HVM_PARAM when booting with ACPI
The kernel will get the event-channel IRQ through
HVM_PARAM_CALLBACK_IRQ.

Signed-off-by: Shannon Zhao <shannon.zhao@linaro.org>
Reviewed-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Reviewed-by: Julien Grall <julien.grall@arm.com>
Tested-by: Julien Grall <julien.grall@arm.com>
2016-07-06 10:34:44 +01:00
Shannon Zhao 3cf4095d74 arm/xen: Use xen_xlate_map_ballooned_pages to setup grant table
Use xen_xlate_map_ballooned_pages to setup grant table. Then it doesn't
rely on DT or ACPI to pass the start address and size of grant table.

Signed-off-by: Shannon Zhao <shannon.zhao@linaro.org>
Acked-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Reviewed-by: Julien Grall <julien.grall@arm.com>
Tested-by: Julien Grall <julien.grall@arm.com>
2016-07-06 10:34:42 +01:00
Stefano Stabellini 7d5f6f81dd xen/arm: set the system time in Xen via the XENPF_settime64 hypercall
If Linux is running as dom0, call XENPF_settime64 to update the system
time in Xen on pvclock_gtod notifications.

Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
2015-12-21 14:40:58 +00:00
Stefano Stabellini e709fba132 xen/arm: introduce xen_read_wallclock
Read the wallclock from the shared info page at boot time.

Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
2015-12-21 14:40:58 +00:00
Stefano Stabellini 72d39c691b xen/arm: introduce HYPERVISOR_platform_op on arm and arm64
Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
2015-12-21 14:40:56 +00:00
Stefano Stabellini 34e38523d5 xen/arm: account for stolen ticks
Register the runstate_memory_area with the hypervisor.
Use pv_time_ops.steal_clock to account for stolen ticks.

Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
2015-12-21 14:40:55 +00:00
Mel Gorman d0164adc89 mm, page_alloc: distinguish between being unable to sleep, unwilling to sleep and avoiding waking kswapd
__GFP_WAIT has been used to identify atomic context in callers that hold
spinlocks or are in interrupts.  They are expected to be high priority and
have access one of two watermarks lower than "min" which can be referred
to as the "atomic reserve".  __GFP_HIGH users get access to the first
lower watermark and can be called the "high priority reserve".

Over time, callers had a requirement to not block when fallback options
were available.  Some have abused __GFP_WAIT leading to a situation where
an optimisitic allocation with a fallback option can access atomic
reserves.

This patch uses __GFP_ATOMIC to identify callers that are truely atomic,
cannot sleep and have no alternative.  High priority users continue to use
__GFP_HIGH.  __GFP_DIRECT_RECLAIM identifies callers that can sleep and
are willing to enter direct reclaim.  __GFP_KSWAPD_RECLAIM to identify
callers that want to wake kswapd for background reclaim.  __GFP_WAIT is
redefined as a caller that is willing to enter direct reclaim and wake
kswapd for background reclaim.

This patch then converts a number of sites

o __GFP_ATOMIC is used by callers that are high priority and have memory
  pools for those requests. GFP_ATOMIC uses this flag.

o Callers that have a limited mempool to guarantee forward progress clear
  __GFP_DIRECT_RECLAIM but keep __GFP_KSWAPD_RECLAIM. bio allocations fall
  into this category where kswapd will still be woken but atomic reserves
  are not used as there is a one-entry mempool to guarantee progress.

o Callers that are checking if they are non-blocking should use the
  helper gfpflags_allow_blocking() where possible. This is because
  checking for __GFP_WAIT as was done historically now can trigger false
  positives. Some exceptions like dm-crypt.c exist where the code intent
  is clearer if __GFP_DIRECT_RECLAIM is used instead of the helper due to
  flag manipulations.

o Callers that built their own GFP flags instead of starting with GFP_KERNEL
  and friends now also need to specify __GFP_KSWAPD_RECLAIM.

The first key hazard to watch out for is callers that removed __GFP_WAIT
and was depending on access to atomic reserves for inconspicuous reasons.
In some cases it may be appropriate for them to use __GFP_HIGH.

The second key hazard is callers that assembled their own combination of
GFP flags instead of starting with something like GFP_KERNEL.  They may
now wish to specify __GFP_KSWAPD_RECLAIM.  It's almost certainly harmless
if it's missed in most cases as other activity will wake kswapd.

Signed-off-by: Mel Gorman <mgorman@techsingularity.net>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Christoph Lameter <cl@linux.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Vitaly Wool <vitalywool@gmail.com>
Cc: Rik van Riel <riel@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-11-06 17:50:42 -08:00
Stefano Stabellini cb9644bf3b xen/arm: don't try to re-register vcpu_info on cpu_hotplug.
Call disable_percpu_irq on CPU_DYING and enable_percpu_irq when the cpu
is coming up.

Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Reviewed-by: Julien Grall <julien.grall@citrix.com>
2015-10-23 14:20:48 +01:00
Juergen Gross d5f985c834 xen/arm: correct comment in enlighten.c
Correct a comment in arch/arm/xen/enlighten.c referencing a wrong
source file.

Signed-off-by: Juergen Gross <jgross@suse.com>
Acked-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Signed-off-by: David Vrabel <david.vrabel@citrix.com>
2015-10-23 14:20:45 +01:00
Julien Grall 9435cce879 xen/swiotlb: Add support for 64KB page granularity
Swiotlb is used on ARM64 to support DMA on platform where devices are
not protected by an SMMU. Furthermore it's only enabled for DOM0.

While Xen is always using 4KB page granularity in the stage-2 page table,
Linux ARM64 may either use 4KB or 64KB. This means that a Linux page
can be spanned accross multiple Xen page.

The Swiotlb code has to validate that the buffer used for DMA is
physically contiguous in the memory. As a Linux page can't be shared
between local memory and foreign page by design (the balloon code always
removing entirely a Linux page), the changes in the code are very
minimal because we only need to check the first Xen PFN.

Note that it may be possible to optimize the function
check_page_physically_contiguous to avoid looping over every Xen PFN
for local memory. Although I will let this optimization for a follow-up.

Signed-off-by: Julien Grall <julien.grall@citrix.com>
Reviewed-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Signed-off-by: David Vrabel <david.vrabel@citrix.com>
2015-10-23 14:20:43 +01:00
Julien Grall 291be10fd7 xen/swiotlb: Pass addresses rather than frame numbers to xen_arch_need_swiotlb
With 64KB page granularity support, the frame number will be different.

It will be easier to modify the behavior in a single place rather than
in each caller.

Signed-off-by: Julien Grall <julien.grall@citrix.com>
Reviewed-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Signed-off-by: David Vrabel <david.vrabel@citrix.com>
2015-10-23 14:20:43 +01:00
Julien Grall 250c9af3d8 arm/xen: Add support for 64KB page granularity
The hypercall interface is always using 4KB page granularity. This is
requiring to use xen page definition macro when we deal with hypercall.

Note that pfn_to_gfn is working with a Xen pfn (i.e 4KB). We may want to
rename pfn_gfn to make this explicit.

We also allocate a 64KB page for the shared page even though only the
first 4KB is used. I don't think this is really important for now as it
helps to have the pointer 4KB aligned (XENMEM_add_to_physmap is taking a
Xen PFN).

Signed-off-by: Julien Grall <julien.grall@citrix.com>
Reviewed-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Signed-off-by: David Vrabel <david.vrabel@citrix.com>
2015-10-23 14:20:42 +01:00
Julien Grall 5ed5451d99 xen/grant-table: Make it running on 64KB granularity
The Xen interface is using 4KB page granularity. This means that each
grant is 4KB.

The current implementation allocates a Linux page per grant. On Linux
using 64KB page granularity, only the first 4KB of the page will be
used.

We could decrease the memory wasted by sharing the page with multiple
grant. It will require some care with the {Set,Clear}ForeignPage macro.

Note that no changes has been made in the x86 code because both Linux
and Xen will only use 4KB page granularity.

Signed-off-by: Julien Grall <julien.grall@citrix.com>
Reviewed-by: David Vrabel <david.vrabel@citrix.com>
Reviewed-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Signed-off-by: David Vrabel <david.vrabel@citrix.com>
2015-10-23 14:20:39 +01:00
Linus Torvalds 57e6bbcb4b Merge branch 'fixes' of git://ftp.arm.linux.org.uk/~rmk/linux-arm
Pull ARM fixes from Russell King:
 "A number of fixes for the merge window, fixing a number of cases
  missed when testing the uaccess code, particularly cases which only
  show up with certain compiler versions"

* 'fixes' of git://ftp.arm.linux.org.uk/~rmk/linux-arm:
  ARM: 8431/1: fix alignement of __bug_table section entries
  arm/xen: Enable user access to the kernel before issuing a privcmd call
  ARM: domains: add memory dependencies to get_domain/set_domain
  ARM: domains: thread_info.h no longer needs asm/domains.h
  ARM: uaccess: fix undefined instruction on ARMv7M/noMMU
  ARM: uaccess: remove unneeded uaccess_save_and_disable macro
  ARM: swpan: fix nwfpe for uaccess changes
  ARM: 8429/1: disable GCC SRA optimization
2015-09-14 12:24:10 -07:00
Julien Grall 0b61f2c0f3 arm/xen: Enable user access to the kernel before issuing a privcmd call
When Xen is copying data to/from the guest it will check if the kernel
has the right to do the access. If not, the hypercall will return an
error.

After the commit a5e090acbf "ARM:
software-based privileged-no-access support", the kernel can't access
any longer the user space by default. This will result to fail on every
hypercall made by the userspace (i.e via privcmd).

We have to enable the userspace access and then restore the correct
permission every time the privcmd is used to made an hypercall.

I didn't find generic helpers to do a these operations, so the change
is only arm32 specific.

Reported-by: Riku Voipio <riku.voipio@linaro.org>
Signed-off-by: Julien Grall <julien.grall@citrix.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2015-09-11 18:50:03 +01:00
Julien Grall a13d7201d7 xen/privcmd: Further s/MFN/GFN/ clean-up
The privcmd code is mixing the usage of GFN and MFN within the same
functions which make the code difficult to understand when you only work
with auto-translated guests.

The privcmd driver is only dealing with GFN so replace all the mention
of MFN into GFN.

The ioctl structure used to map foreign change has been left unchanged
given that the userspace is using it. Nonetheless, add a comment to
explain the expected value within the "mfn" field.

Signed-off-by: Julien Grall <julien.grall@citrix.com>
Reviewed-by: David Vrabel <david.vrabel@citrix.com>
Signed-off-by: David Vrabel <david.vrabel@citrix.com>
2015-09-08 18:03:54 +01:00
Julien Grall 32e09870ee xen: Make clear that swiotlb and biomerge are dealing with DMA address
The swiotlb is required when programming a DMA address on ARM when a
device is not protected by an IOMMU.

In this case, the DMA address should always be equal to the machine address.
For DOM0 memory, Xen ensure it by have an identity mapping between the
guest address and host address. However, when mapping a foreign grant
reference, the 1:1 model doesn't work.

For ARM guest, most of the callers of pfn_to_mfn expects to get a GFN
(Guest Frame Number), i.e a PFN (Page Frame Number) from the Linux point
of view given that all ARM guest are auto-translated.

Even though the name pfn_to_mfn is misleading, we need to ensure that
those caller get a GFN and not by mistake a MFN. In pratical, I haven't
seen error related to this but we should fix it for the sake of
correctness.

In order to fix the implementation of pfn_to_mfn on ARM in a follow-up
patch, we have to introduce new helpers to return the DMA from a PFN and
the invert.

On x86, the new helpers will be an alias of pfn_to_mfn and mfn_to_pfn.

The helpers will be used in swiotlb and xen_biovec_phys_mergeable.

This is necessary in the latter because we have to ensure that the
biovec code will not try to merge a biovec using foreign page and
another using Linux memory.

Lastly, the helper mfn_to_local_pfn has been renamed to bfn_to_local_pfn
given that the only usage was in swiotlb.

Signed-off-by: Julien Grall <julien.grall@citrix.com>
Reviewed-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Signed-off-by: David Vrabel <david.vrabel@citrix.com>
2015-09-08 17:10:52 +01:00
Julien Grall 7ed208ef4e arm/xen: Drop the definition of xen_pci_platform_unplug
The commit 6f6c15ef91 "xen/pvhvm: Remove
the xen_platform_pci int." makes the x86 version of
xen_pci_platform_unplug static.

Therefore we don't need anymore to define a dummy xen_pci_platform_unplug
for ARM.

Signed-off-by: Julien Grall <julien.grall@citrix.com>
Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
2015-08-20 12:24:16 +01:00
Julien Grall 4a5b69464e xen/events: Support event channel rebind on ARM
Currently, the event channel rebind code is gated with the presence of
the vector callback.

The virtual interrupt controller on ARM has the concept of per-CPU
interrupt (PPI) which allow us to support per-VCPU event channel.
Therefore there is no need of vector callback for ARM.

Xen is already using a free PPI to notify the guest VCPU of an event.
Furthermore, the xen code initialization in Linux (see
arch/arm/xen/enlighten.c) is requesting correctly a per-CPU IRQ.

Introduce new helper xen_support_evtchn_rebind to allow architecture
decide whether rebind an event is support or not. It will always return
true on ARM and keep the same behavior on x86.

This is also allow us to drop the usage of xen_have_vector_callback
entirely in the ARM code.

Signed-off-by: Julien Grall <julien.grall@citrix.com>
Signed-off-by: David Vrabel <david.vrabel@citrix.com>
2015-08-20 12:24:15 +01:00
Julien Grall a9fd60e268 xen: Include xen/page.h rather than asm/xen/page.h
Using xen/page.h will be necessary later for using common xen page
helpers.

As xen/page.h already include asm/xen/page.h, always use the later.

Signed-off-by: Julien Grall <julien.grall@citrix.com>
Reviewed-by: David Vrabel <david.vrabel@citrix.com>
Cc: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Cc: Ian Campbell <ian.campbell@citrix.com>
Cc: Wei Liu <wei.liu2@citrix.com>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: netdev@vger.kernel.org
Signed-off-by: David Vrabel <david.vrabel@citrix.com>
2015-06-17 16:14:18 +01:00
Ard Biesheuvel f1dddd118c xen/arm: allow console=hvc0 to be omitted for guests
From: Ard Biesheuvel <ard.biesheuvel@linaro.org>

This patch registers hvc0 as the preferred console if no console
has been specified explicitly on the kernel command line.

The purpose is to allow platform agnostic kernels and boot images
(such as distro installers) to boot in a Xen/ARM domU without the
need to modify the command line by hand.

Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Reviewed-by: Julien Grall <julien.grall@linaro.org>
2015-05-28 12:23:11 +01:00
Stefano Stabellini 5882bfef63 arm,arm64/xen: move Xen initialization earlier
Currently, Xen is initialized/discovered in an initcall. This doesn't
allow us to support earlyprintk or choosing the preferred console when
running on Xen.

The current function xen_guest_init is now split in 2 parts:
    - xen_early_init: Check if there is a Xen node in the device tree
    and setup domain type
    - xen_guest_init: Retrieve the information from the device node and
    initialize Xen (grant table, shared page...)

The former is called in setup_arch, while the latter is an initcall.

Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Signed-off-by: Julien Grall <julien.grall@linaro.org>
Acked-by: Ian Campbell <ian.campbell@citrix.com>
Acked-by: Will Deacon <will.deacon@arm.com>
2015-05-28 12:23:11 +01:00
Julien Grall 81e863c3a2 arm/xen: Correctly check if the event channel interrupt is present
The function irq_of_parse_and_map returns 0 when the IRQ is not found.

Futhermore, move the check before notifying the user that we are running on
Xen.

Signed-off-by: Julien Grall <julien.grall@linaro.org>
Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Acked-by: Ian Campbell <ian.campbell@citrix.com>
2015-05-28 12:23:10 +01:00
Boris Ostrovsky ffb7dbed47 xen/arm: Define xen_arch_suspend()
Commit 2b953a5e99 ("xen: Suspend ticks on all CPUs during suspend")
introduced xen_arch_suspend() routine but did so only for x86, breaking
ARM builds.

We need to add it to ARM as well.

Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Reported-by: Michal Suchanek <hramrach@gmail.com>
Tested-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Signed-off-by: David Vrabel <david.vrabel@citrix.com>
2015-05-18 13:38:09 +01:00
Stefano Stabellini 8746515d7f xen: Add __GFP_DMA flag when xen_swiotlb_init gets free pages on ARM
Make sure that xen_swiotlb_init allocates buffers that are DMA capable
when at least one memblock is available below 4G. Otherwise we assume
that all devices on the SoC can cope with >4G addresses. We do this on
ARM and ARM64, where dom0 is mapped 1:1, so pfn == mfn in this case.

No functional changes on x86.

From: Chen Baozi <baozich@gmail.com>

Signed-off-by: Chen Baozi <baozich@gmail.com>
Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Tested-by: Chen Baozi <baozich@gmail.com>
Acked-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: David Vrabel <david.vrabel@citrix.com>
2015-05-06 15:02:58 +01:00
David Vrabel 4e8c0c8c4b xen/privcmd: improve performance of MMAPBATCH_V2
Make the IOCTL_PRIVCMD_MMAPBATCH_V2 (and older V1 version) map
multiple frames at a time rather than one at a time, despite the pages
being non-consecutive GFNs.

xen_remap_foreign_mfn_array() is added which maps an array of GFNs
(instead of a consecutive range of GFNs).

Since per-frame errors are returned in an array, privcmd must set the
MMAPBATCH_V1 error bits as part of the "report errors" phase, after
all the frames are mapped.

Migrate times are significantly improved (when using a PV toolstack
domain).  For example, for an idle 12 GiB PV guest:

        Before     After
  real  0m38.179s  0m26.868s
  user  0m15.096s  0m13.652s
  sys   0m28.988s  0m18.732s

Signed-off-by: David Vrabel <david.vrabel@citrix.com>
Reviewed-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
2015-03-16 14:49:15 +00:00
David Vrabel 628c28eefd xen: unify foreign GFN map/unmap for auto-xlated physmap guests
Auto-translated physmap guests (arm, arm64 and x86 PVHVM/PVH) map and
unmap foreign GFNs using the same method (updating the physmap).
Unify the two arm and x86 implementations into one commont one.

Note that on arm and arm64, the correct error code will be returned
(instead of always -EFAULT) and map/unmap failure warnings are no
longer printed.  These changes are required if the foreign domain is
paging (-ENOENT failures are expected and must be propagated up to the
caller).

Signed-off-by: David Vrabel <david.vrabel@citrix.com>
Reviewed-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
2015-03-16 14:49:15 +00:00
David Vrabel 853d028934 xen/grant-table: pre-populate kernel unmap ops for xen_gnttab_unmap_refs()
When unmapping grants, instead of converting the kernel map ops to
unmap ops on the fly, pre-populate the set of unmap ops.

This allows the grant unmap for the kernel mappings to be trivially
batched in the future.

Signed-off-by: David Vrabel <david.vrabel@citrix.com>
Reviewed-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
2015-01-28 14:03:10 +00:00
Chuck Tuffli 35c8ab4c5c arm64: Relax licensing of arm64 Xen DMA operations
With Xen configured into the arm64 kernel, any driver allocating
DMA'able memory for PCI operations, must be GPL compatible, regardless
of its interaction with Xen. This patch relaxes the GPL requirement of
xen_dma_ops and its dependencies to allow open source drivers to be
compiled for the arm64 architecture.

Signed-off-by: Chuck Tuffli <chuck.tuffli@emulex.com>
2015-01-20 18:44:23 +00:00
Stefano Stabellini da095a9960 xen/arm: introduce GNTTABOP_cache_flush
Introduce support for new hypercall GNTTABOP_cache_flush.
Use it to perform cache flashing on pages used for dma when necessary.

If GNTTABOP_cache_flush is supported by the hypervisor, we don't need to
bounce dma map operations that involve foreign grants and non-coherent
devices.

Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Acked-by: Ian Campbell <ian.campbell@citrix.com>
2014-12-04 12:41:54 +00:00
Stefano Stabellini a4dba13089 xen/arm/arm64: introduce xen_arch_need_swiotlb
Introduce an arch specific function to find out whether a particular dma
mapping operation needs to bounce on the swiotlb buffer.

On ARM and ARM64, if the page involved is a foreign page and the device
is not coherent, we need to bounce because at unmap time we cannot
execute any required cache maintenance operations (we don't know how to
find the pfn from the mfn).

No change of behaviour for x86.

Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Reviewed-by: David Vrabel <david.vrabel@citrix.com>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Acked-by: Ian Campbell <ian.campbell@citrix.com>
Acked-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2014-12-04 12:41:54 +00:00
Stefano Stabellini 5121872afe xen/arm/arm64: merge xen/mm32.c into xen/mm.c
Merge xen/mm32.c into xen/mm.c.
As a consequence the code gets compiled on arm64 too.

Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
2014-12-04 12:41:53 +00:00
Stefano Stabellini 3567258d28 xen/arm: use hypercall to flush caches in map_page
In xen_dma_map_page, if the page is a local page, call the native
map_page dma_ops. If the page is foreign, call __xen_dma_map_page that
issues any required cache maintenane operations via hypercall.

The reason for doing this is that the native dma_ops map_page could
allocate buffers than need to be freed. If the page is foreign we don't
call the native unmap_page dma_ops function, resulting in a memory leak.

Suggested-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
2014-12-04 12:41:52 +00:00
Stefano Stabellini 2e2a7817fd xen/arm: use is_device_dma_coherent
Use is_device_dma_coherent to check whether we need to issue cache
maintenance operations rather than checking on the existence of a
particular dma_ops function for the device.

This is correct because coherent devices don't need cache maintenance
operations - arm_coherent_dma_ops does not set the hooks that we
were previously checking for existance.

Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Acked-by: Ian Campbell <ian.campbell@citrix.com>
2014-12-04 12:41:51 +00:00
Stefano Stabellini 2f91fc331a xen/arm: if(pfn_valid(pfn)) call native dma_ops
Remove code duplication in mm32.c by calling the native dma_ops if the
page is a local page (not a foreign page). Use a simple pfn_valid(pfn)
check to figure out if the page is local, exploiting the fact that dom0
is mapped 1:1, therefore pfn_valid always returns false when called on a
foreign mfn.

Suggested-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
2014-12-04 12:41:48 +00:00
Stefano Stabellini 35e0be88c4 xen/arm: remove outer_*_range call
Dom0 is not actually capable of issuing outer_inv_range or
outer_clean_range calls.

Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Acked-by: Ian Campbell <ian.campbell@citrix.com>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
2014-12-04 12:41:47 +00:00
Stefano Stabellini e9e87eb3f9 xen/arm: remove handling of XENFEAT_grant_map_identity
The feature has been removed from Xen. Also Linux cannot use it on ARM32
without CONFIG_ARM_LPAE.

Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Acked-by: Ian Campbell <ian.campbell@citrix.com>
Reviewed-by: David Vrabel <david.vrabel@citrix.com>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
2014-12-04 12:41:45 +00:00
Stefano Stabellini d50582e06f xen/arm: remove mach_to_phys rbtree
Remove the rbtree used to keep track of machine to physical mappings:
the frontend can grant the same page multiple times, leading to errors
inserting or removing entries from the mach_to_phys tree.

Linux only needed to know the physical address corresponding to a given
machine address in swiotlb-xen. Now that swiotlb-xen can call the
xen_dma_* functions passing the machine address directly, we can remove
it.

Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Tested-by: Denis Schneider <v1ne2go@gmail.com>
2014-09-11 18:11:53 +00:00
Stefano Stabellini 340720be32 xen/arm: reimplement xen_dma_unmap_page & friends
xen_dma_unmap_page, xen_dma_sync_single_for_cpu and
xen_dma_sync_single_for_device are currently implemented by calling into
the corresponding generic ARM implementation of these functions. In
order to do this, firstly the dma_addr_t handle, that on Xen is a
machine address, needs to be translated into a physical address.  The
operation is expensive and inaccurate, given that a single machine
address can correspond to multiple physical addresses in one domain,
because the same page can be granted multiple times by the frontend.

To avoid this problem, we introduce a Xen specific implementation of
xen_dma_unmap_page, xen_dma_sync_single_for_cpu and
xen_dma_sync_single_for_device, that can operate on machine addresses
directly.

The new implementation relies on the fact that the hypervisor creates a
second p2m mapping of any grant pages at physical address == machine
address of the page for dom0. Therefore we can access memory at physical
address == dma_addr_r handle and perform the cache flushing there. Some
cache maintenance operations require a virtual address. Instead of using
ioremap_cache, that is not safe in interrupt context, we allocate a
per-cpu PAGE_KERNEL scratch page and we manually update the pte for it.

arm64 doesn't need cache maintenance operations on unmap for now.

Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Tested-by: Denis Schneider <v1ne2go@gmail.com>
2014-09-11 18:11:53 +00:00
Stefano Stabellini 5ebc77de83 xen/arm: introduce XENFEAT_grant_map_identity
The flag tells us that the hypervisor maps a grant page to guest
physical address == machine address of the page in addition to the
normal grant mapping address. It is needed to properly issue cache
maintenance operation at the completion of a DMA operation involving a
foreign grant.

Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Tested-by: Denis Schneider <v1ne2go@gmail.com>
2014-09-11 18:11:52 +00:00
David Vrabel ac80c77003 arm/xen: remove duplicate arch_gnttab_init() function
This was introduced in commit e306e3be1c (Merge tag
'stable/for-linus-3.17-rc0-tag').

Signed-off-by: David Vrabel <david.vrabel@citrix.com>
Acked-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
2014-08-11 11:59:14 +01:00
Linus Torvalds e306e3be1c - Remove unused V2 grant table support.
- Note that Konrad is xen-blkkback/front maintainer.
 - Add 'xen_nopv' option to disable PV extentions for x86 HVM guests.
 - Misc. minor cleanups.
 -----BEGIN PGP SIGNATURE-----
 Version: GnuPG v1.4.12 (GNU/Linux)
 
 iQEcBAABAgAGBQJT4N57AAoJEFxbo/MsZsTRtfsH/2GxmloKqMZqusnz5PR/x2hd
 M3aXtDw36rxv3hEciIs/NX6obMenRdofDKXVMafnU/gw+EOBQQQ2n/nDqcLOSN+0
 hVyrKHgByYQKaeAhAbrGiGIkuoe5JAURsaggx/YlYSx3hkE0za1XmcUjkPFEVP3l
 UeXXJ40H9hHgESsDwd1UQ08YNtvwdaWVHJAjio3jSxCBAHnAPhCqPhKVy/6LOr+U
 T6HgYsX9HLQRYBy34OOYfKBFnGOJpstnZJd3hMTYtrF4xaTl/Cnf+YxKxv/XJtGD
 YHukhQaEyws7RaDAXK1Uty1hlqgzDoVcFz1TixJIrF6YaO2QhhjMa/oYkbBW09s=
 =Ojrz
 -----END PGP SIGNATURE-----

Merge tag 'stable/for-linus-3.17-rc0-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip

Pull Xen updates from David Vrabel:
 - remove unused V2 grant table support
 - note that Konrad is xen-blkkback/front maintainer
 - add 'xen_nopv' option to disable PV extentions for x86 HVM guests
 - misc minor cleanups

* tag 'stable/for-linus-3.17-rc0-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip:
  xen-pciback: Document the 'quirks' sysfs file
  xen/pciback: Fix error return code in xen_pcibk_attach()
  xen/events: drop negativity check of unsigned parameter
  xen/setup: Remove Identity Map Debug Message
  xen/events/fifo: remove a unecessary use of BM()
  xen/events/fifo: ensure all bitops are properly aligned even on x86
  xen/events/fifo: reset control block and local HEADs on resume
  xen/arm: use BUG_ON
  xen/grant-table: remove support for V2 tables
  x86/xen: safely map and unmap grant frames when in atomic context
  MAINTAINERS: Make me the Xen block subsystem (front and back) maintainer
  xen: Introduce 'xen_nopv' to disable PV extensions for HVM guests.
2014-08-07 11:33:15 -07:00
Linus Torvalds c489d98c8c Merge branch 'for-linus' of git://ftp.arm.linux.org.uk/~rmk/linux-arm
Pull ARM updates from Russell King:
 "Included in this update:

   - perf updates from Will Deacon:

     The main changes are callchain stability fixes from Jean Pihet and
     event mapping and PMU name rework from Mark Rutland

     The latter is preparatory work for enabling some code re-use with
     arm64 in the future.

   - updates for nommu from Uwe Kleine-König:

     Two different fixes for the same problem making some ARM nommu
     configurations not boot since 3.6-rc1.  The problem is that
     user_addr_max returned the biggest available RAM address which
     makes some copy_from_user variants fail to read from XIP memory.

   - deprecate legacy OMAP DMA API, in preparation for it's removal.

     The popular drivers have been converted over, leaving a very small
     number of rarely used drivers, which hopefully can be converted
     during the next cycle with a bit more visibility (and hopefully
     people popping out of the woodwork to help test)

   - more tweaks for BE systems, particularly with the kernel image
     format.  In connection with this, I've cleaned up the way we
     generate the linker script for the decompressor.

   - removal of hard-coded assumptions of the kernel stack size, making
     everywhere depend on the value of THREAD_SIZE_ORDER.

   - MCPM updates from Nicolas Pitre.

   - Make it easier for proper CPU part number checks (which should
     always include the vendor field).

   - Assembly code optimisation - use the "bx" instruction when
     returning from a function on ARMv6+ rather than "mov pc, reg".

   - Save the last kernel misaligned fault location and report it via
     the procfs alignment file.

   - Clean up the way we create the initial stack frame, which is a
     repeated pattern in several different locations.

   - Support for 8-byte get_user(), needed for some DRM implementations.

   - mcs locking from Will Deacon.

   - Save and restore a few more Cortex-A9 registers (for errata
     workarounds)

   - Fix various aspects of the SWP emulation, and the ELF hwcap for the
     SWP instruction.

   - Update LPAE logic for pte_write and pmd_write to make it more
     correct.

   - Support for Broadcom Brahma15 CPU cores.

   - ARM assembly crypto updates from Ard Biesheuvel"

* 'for-linus' of git://ftp.arm.linux.org.uk/~rmk/linux-arm: (53 commits)
  ARM: add comments to the early page table remap code
  ARM: 8122/1: smp_scu: enable SCU standby support
  ARM: 8121/1: smp_scu: use macro for SCU enable bit
  ARM: 8120/1: crypto: sha512: add ARM NEON implementation
  ARM: 8119/1: crypto: sha1: add ARM NEON implementation
  ARM: 8118/1: crypto: sha1/make use of common SHA-1 structures
  ARM: 8113/1: remove remaining definitions of PLAT_PHYS_OFFSET from <mach/memory.h>
  ARM: 8111/1: Enable erratum 798181 for Broadcom Brahma-B15
  ARM: 8110/1: do CPU-specific init for Broadcom Brahma15 cores
  ARM: 8109/1: mm: Modify pte_write and pmd_write logic for LPAE
  ARM: 8108/1: mm: Introduce {pte,pmd}_isset and {pte,pmd}_isclear
  ARM: hwcap: disable HWCAP_SWP if the CPU advertises it has exclusives
  ARM: SWP emulation: only initialise on ARMv7 CPUs
  ARM: SWP emulation: always enable when SMP is enabled
  ARM: 8103/1: save/restore Cortex-A9 CP15 registers on suspend/resume
  ARM: 8098/1: mcs lock: implement wfe-based polling for MCS locking
  ARM: 8091/2: add get_user() support for 8 byte types
  ARM: 8097/1: unistd.h: relocate comments back to place
  ARM: 8096/1: Describe required sort order for textofs-y (TEXT_OFFSET)
  ARM: 8090/1: add revision info for PL310 errata 588369 and 727915
  ...
2014-08-05 10:05:29 -07:00