It's a bit silly to repeatedly call domain_flush_cache() for each PTE
individually, as we clear it. Instead, batch them up and flush a whole
range at a time. We might as well refrain from recalculating the PTE
address from scratch each time round the loop too.
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
This is fairly broken anyway -- it doesn't take hotplug into account.
We should probably be checking page_is_ram() instead.
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
Most of its callers are having to shift for themselves anyway, so we might
as well do it in iommu_flush_iotlb_psi().
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
... and use it in the trivial cases; the other callers want individual
(and bisectable) attention, since I screwed them up the first time...
Make the BUG_ON() happen on too-large virtual address rather than
physical address, too. That's the one we care about.
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
Use unaligned address for domain->max_addr. That algorithm isn't ideal
anyway -- we should probably just look at the last iova in the tree.
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
With some cleanup of intel_unmap_page(), intel_unmap_sg() and
vm_domain_exit() to no longer play with 64-bit addresses.
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
Add some helpers for converting between VT-d and normal system pfns,
since system pages can be larger than VT-d pages.
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
There's no need for the GFX workaround now we have 'iommu=pt' for the
cases where people really care about performance. There's no need to
have a special case for just one type of device.
This also speeds up the iommu=pt path and reduces memory usage by
setting up the si_domain _once_ and then using it for all devices,
rather than giving each device its own private page tables.
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
In caching mode, domain ID 0 is reserved for non-present to present
mapping flush. Device IOTLB doesn't need to be flushed in this case.
Previously we were avoiding the flush for domain zero, even if the IOMMU
wasn't in caching mode and domain zero wasn't special.
Signed-off-by: Yu Zhao <yu.zhao@intel.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
Drop the e820 scanning and use existing function for finding valid
RAM regions to add to 1:1 mapping.
Signed-off-by: Chris Wright <chrisw@redhat.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
Identity mapping for IOMMU defines a single domain to 1:1 map all PCI
devices to all usable memory.
This reduces map/unmap overhead in DMA API's and improve IOMMU
performance. On 10Gb network cards, Netperf shows no performance
degradation compared to non-IOMMU performance.
This method may lose some of DMA remapping benefits like isolation.
The patch sets up identity mapping for all PCI devices to all usable
memory. In the DMA API, there is no overhead to maintain page tables,
invalidate iotlb, flush cache etc.
32 bit DMA devices don't use identity mapping domain, in order to access
memory beyond 4GiB.
When kernel option iommu=pt, pass through is first tried. If pass
through succeeds, IOMMU goes to pass through. If pass through is not
supported in hw or fail for whatever reason, IOMMU goes to identity
mapping.
Signed-off-by: Fenghua Yu <fenghua.yu@intel.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
Enable the device IOTLB (i.e. ATS) for both the bare metal and KVM
environments.
Signed-off-by: Yu Zhao <yu.zhao@intel.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
Make iommu_flush_iotlb_psi() and flush_unmaps() more readable.
Signed-off-by: Yu Zhao <yu.zhao@intel.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
PAGE_MASK is 0xFFFFF000 on i386 -- even with PAE.
So it's not sufficient to ensure that you use phys_addr_t or uint64_t
everywhere you handle physical addresses -- you also have to avoid using
the construct 'addr & PAGE_MASK', because that will strip the high 32
bits of the address.
This patch avoids that problem by using PHYSICAL_PAGE_MASK instead of
PAGE_MASK where appropriate. It leaves '& PAGE_MASK' in a few instances
that don't matter -- where it's being used on the virtual bus addresses
we're dishing out, which are 32-bit anyway.
Since PHYSICAL_PAGE_MASK is not present on other architectures, we have
to define it (to PAGE_MASK) if it's not already defined.
Maybe it would be better just to fix PAGE_MASK for i386/PAE?
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
In iommu_flush_write_buffer() we read iommu->gcmd before taking the
register_lock, and then we mask in the WBF bit and write it to the
register.
There is a tiny chance that something else could have _changed_
iommu->gcmd before we take the lock, but after we read it. So we could
be undoing that change.
Never actually going to have happened in practice, since nothing else
changes that register at runtime -- aside from the write-buffer flush
it's only ever touched at startup for enabling translation, etc.
But worth fixing anyway.
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
As we just did for context cache flushing, clean up the logic around
whether we need to flush the iotlb or just the write-buffer, depending
on caching mode.
Fix the same bug in qi_flush_iotlb() that qi_flush_context() had -- it
isn't supposed to be returning an error; it's supposed to be returning a
flag which triggers a write-buffer flush.
Remove some superfluous conditional write-buffer flushes which could
never have happened because they weren't for non-present-to-present
mapping changes anyway.
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
It really doesn't make a lot of sense to have some of the logic to
handle caching vs. non-caching mode duplicated in qi_flush_context() and
__iommu_flush_context(), while the return value indicates whether the
caller should take other action which depends on the same thing.
Especially since qi_flush_context() thought it was returning something
entirely different anyway.
This patch makes qi_flush_context() and __iommu_flush_context() both
return void, removes the 'non_present_entry_flush' argument and makes
the only call site which _set_ that argument to 1 do the right thing.
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
The domain->id is a sequence number associated with the KVM guest
and should not be used for the context flush. This patch replaces
the domain->id with a proper id value for both bare metal and KVM.
Signed-off-by: Yu Zhao <yu.zhao@intel.com>
Acked-by: Weidong Han <weidong.han@intel.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
This updated patch should fix the compiling errors and remove the extern
iommu_pass_through from drivers/pci/intel-iommu.c file.
Signed-off-by: Fenghua Yu <fenghua.yu@intel.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
The patch adds kernel parameter intel_iommu=pt to set up pass through
mode in context mapping entry. This disables DMAR in linux kernel; but
KVM still runs on VT-d and interrupt remapping still works.
In this mode, kernel uses swiotlb for DMA API functions but other VT-d
functionalities are enabled for KVM. KVM always uses multi level
translation page table in VT-d. By default, pass though mode is disabled
in kernel.
This is useful when people don't want to enable VT-d DMAR in kernel but
still want to use KVM and interrupt remapping for reasons like DMAR
performance concern or debug purpose.
Signed-off-by: Fenghua Yu <fenghua.yu@intel.com>
Acked-by: Weidong Han <weidong@intel.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
Currently, when x2apic is not enabled, interrupt remapping
will be enabled in init_dmars(), where it is too late to remap
ioapic interrupts, that is, ioapic interrupts are really in
compatibility mode, not remappable mode.
This patch always enables interrupt remapping before ioapic
setup, it guarantees all interrupts will be remapped when
interrupt remapping is enabled. Thus it doesn't need to set
the compatibility interrupt bit.
[ Impact: refactor intr-remap init sequence, enable fuller remap mode ]
Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com>
Signed-off-by: Weidong Han <weidong.han@intel.com>
Acked-by: David Woodhouse <David.Woodhouse@intel.com>
Cc: iommu@lists.linux-foundation.org
Cc: allen.m.kay@intel.com
Cc: fenghua.yu@intel.com
LKML-Reference: <1239957736-6161-4-git-send-email-weidong.han@intel.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Replace all DMA_32BIT_MASK macro with DMA_BIT_MASK(32)
Signed-off-by: Yang Hongyang<yanghy@cn.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Replace all DMA_64BIT_MASK macro with DMA_BIT_MASK(64)
Signed-off-by: Yang Hongyang<yanghy@cn.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This issue was pointed out by Linus.
In dma_pte_clear_range() in intel-iommu.c
start = PAGE_ALIGN(start);
end &= PAGE_MASK;
npages = (end - start) / VTD_PAGE_SIZE;
In partial page case, start could be bigger than end and npages will be
negative.
Currently the issue doesn't show up as a real bug in because start and
end have been aligned to page boundary already by all callers. So the
issue has been hidden. But it is dangerous programming practice.
Signed-off-by: Fenghua Yu <fenghua.yu@intel.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
It's possible for a device in the drhd->devices[] array to be NULL if
it wasn't found at boot time, which means we have to check for that
case.
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
We were comparing {bus,devfn} and assuming that a match meant it was the
same device. It doesn't -- the same {bus,devfn} can exist in
multiple PCI domains. Include domain number in device identification
(and call it 'segment' in most places, because there's already a lot of
references to 'domain' which means something else, and this code is
infected with ACPI thinking already).
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
When the DMAR table identifies that a PCI-PCI bridge belongs to a given
IOMMU, that means that the bridge and all devices behind it should be
associated with the IOMMU. Not just the bridge itself.
This fixes the device_to_iommu() function accordingly.
(It's broken if you have the same PCI bus numbers in multiple domains,
but this function was always broken in that way; I'll be dealing with
that later).
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
interrupt remapping must be enabled before enabling x2apic, but
interrupt remapping doesn't depend on x2apic, it can be used
separately. Enable interrupt remapping in init_dmars even x2apic
is not supported.
[dwmw2: Update Kconfig accordingly, fix build with INTR_REMAP && !X2APIC]
Signed-off-by: Weidong Han <weidong.han@intel.com>
Acked-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
This patch implements the suspend and resume feature for Intel IOMMU
DMAR. It hooks to kernel suspend and resume interface. When suspend happens, it
saves necessary hardware registers. When resume happens, it restores the
registers and restarts IOMMU by enabling translation, setting up root entry, and
re-enabling queued invalidation.
Signed-off-by: Fenghua Yu <fenghua.yu@intel.com>
Acked-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
The problem is in dma_pte_clear_range and dma_pte_free_pagetable. When
intel_unmap_single and intel_unmap_sg call them, the end address may be
zero if the 'start_addr + size' rounds up. So no PTE gets cleared. The
uncleared PTE fires the BUG_ON when it's used again to create new mappings.
After I modified dma_pte_clear_range a bit, the BUG_ON is gone.
Tested both 32 and 32 PAE modes on Intel X58 and Q35 platforms.
Signed-off-by: Yu Zhao <yu.zhao@intel.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
If we fix a few highmem-related thinkos and a couple of printk format
warnings, the Intel IOMMU driver works fine in a 32-bit kernel.
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
When assign a device behind conventional PCI bridge or PCIe to
PCI/PCI-x bridge to a domain, it must assign its bridge and may
also need to assign secondary interface to the same domain.
Dependent assignment is already there, but dependent
deassignment is missed when detach device from virtual machine.
This results in conventional PCI device assignment failure after
it has been assigned once. This patch addes dependent
deassignment, and fixes the issue.
Signed-off-by: Weidong Han <weidong.han@intel.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
The user can request to enable snooping control through VT-d page table.
Signed-off-by: Sheng Yang <sheng@linux.intel.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
This iommu_op can tell if domain have a specific capability, like snooping
control for Intel IOMMU, which can be used by other components of kernel to
adjust the behaviour.
Signed-off-by: Sheng Yang <sheng@linux.intel.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
David Woodhouse