Commit Graph

24 Commits (c43267e6794a36013fd495a4d81bf7f748fe4615)

Author SHA1 Message Date
Will Deacon a371003560 arm64: mm: Push __TLBI_VADDR() into __tlbi_level()
The __TLBI_VADDR() macro takes an ASID and an address and converts them
into a single argument formatted correctly for a TLB invalidation
instruction.

Rather than have callers worry about this (especially in the case where
the ASID is zero), push the macro down into __tlbi_level() via a new
__tlbi_level_asid() helper.

Signed-off-by: Will Deacon <will@kernel.org>
Reviewed-by: Linu Cherian <linu.cherian@arm.com>
Reviewed-by: Jonathan Cameron <jonathan.cameron@huawei.com>
Signed-off-by: Ryan Roberts <ryan.roberts@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2026-03-13 17:23:03 +00:00
Mark Rutland a8f78680ee arm64: tlb: Optimize ARM64_WORKAROUND_REPEAT_TLBI
The ARM64_WORKAROUND_REPEAT_TLBI workaround is used to mitigate several
errata where broadcast TLBI;DSB sequences don't provide all the
architecturally required synchronization. The workaround performs more
work than necessary, and can have significant overhead. This patch
optimizes the workaround, as explained below.

The workaround was originally added for Qualcomm Falkor erratum 1009 in
commit:

  d9ff80f83e ("arm64: Work around Falkor erratum 1009")

As noted in the message for that commit, the workaround is applied even
in cases where it is not strictly necessary.

The workaround was later reused without changes for:

* Arm Cortex-A76 erratum #1286807
  SDEN v33: https://developer.arm.com/documentation/SDEN-885749/33-0/

* Arm Cortex-A55 erratum #2441007
  SDEN v16: https://developer.arm.com/documentation/SDEN-859338/1600/

* Arm Cortex-A510 erratum #2441009
  SDEN v19: https://developer.arm.com/documentation/SDEN-1873351/1900/

The important details to note are as follows:

1. All relevant errata only affect the ordering and/or completion of
   memory accesses which have been translated by an invalidated TLB
   entry. The actual invalidation of TLB entries is unaffected.

2. The existing workaround is applied to both broadcast and local TLB
   invalidation, whereas for all relevant errata it is only necessary to
   apply a workaround for broadcast invalidation.

3. The existing workaround replaces every TLBI with a TLBI;DSB;TLBI
   sequence, whereas for all relevant errata it is only necessary to
   execute a single additional TLBI;DSB sequence after any number of
   TLBIs are completed by a DSB.

   For example, for a sequence of batched TLBIs:

       TLBI <op1>[, <arg1>]
       TLBI <op2>[, <arg2>]
       TLBI <op3>[, <arg3>]
       DSB ISH

   ... the existing workaround will expand this to:

       TLBI <op1>[, <arg1>]
       DSB ISH                  // additional
       TLBI <op1>[, <arg1>]     // additional
       TLBI <op2>[, <arg2>]
       DSB ISH                  // additional
       TLBI <op2>[, <arg2>]     // additional
       TLBI <op3>[, <arg3>]
       DSB ISH                  // additional
       TLBI <op3>[, <arg3>]     // additional
       DSB ISH

   ... whereas it is sufficient to have:

       TLBI <op1>[, <arg1>]
       TLBI <op2>[, <arg2>]
       TLBI <op3>[, <arg3>]
       DSB ISH
       TLBI <opX>[, <argX>]     // additional
       DSB ISH                  // additional

   Using a single additional TBLI and DSB at the end of the sequence can
   have significantly lower overhead as each DSB which completes a TLBI
   must synchronize with other PEs in the system, with potential
   performance effects both locally and system-wide.

4. The existing workaround repeats each specific TLBI operation, whereas
   for all relevant errata it is sufficient for the additional TLBI to
   use *any* operation which will be broadcast, regardless of which
   translation regime or stage of translation the operation applies to.

   For example, for a single TLBI:

       TLBI ALLE2IS
       DSB ISH

   ... the existing workaround will expand this to:

       TLBI ALLE2IS
       DSB ISH
       TLBI ALLE2IS             // additional
       DSB ISH                  // additional

   ... whereas it is sufficient to have:

       TLBI ALLE2IS
       DSB ISH
       TLBI VALE1IS, XZR        // additional
       DSB ISH                  // additional

   As the additional TLBI doesn't have to match a specific earlier TLBI,
   the additional TLBI can be implemented in separate code, with no
   memory of the earlier TLBIs. The additional TLBI can also use a
   cheaper TLBI operation.

5. The existing workaround is applied to both Stage-1 and Stage-2 TLB
   invalidation, whereas for all relevant errata it is only necessary to
   apply a workaround for Stage-1 invalidation.

   Architecturally, TLBI operations which invalidate only Stage-2
   information (e.g. IPAS2E1IS) are not required to invalidate TLB
   entries which combine information from Stage-1 and Stage-2
   translation table entries, and consequently may not complete memory
   accesses translated by those combined entries. In these cases,
   completion of memory accesses is only guaranteed after subsequent
   invalidation of Stage-1 information (e.g. VMALLE1IS).

Taking the above points into account, this patch reworks the workaround
logic to reduce overhead:

* New __tlbi_sync_s1ish() and __tlbi_sync_s1ish_hyp() functions are
  added and used in place of any dsb(ish) which is used to complete
  broadcast Stage-1 TLB maintenance. When the
  ARM64_WORKAROUND_REPEAT_TLBI workaround is enabled, these helpers will
  execute an additional TLBI;DSB sequence.

  For consistency, it might make sense to add __tlbi_sync_*() helpers
  for local and stage 2 maintenance. For now I've left those with
  open-coded dsb() to keep the diff small.

* The duplication of TLBIs in __TLBI_0() and __TLBI_1() is removed. This
  is no longer needed as the necessary synchronization will happen in
  __tlbi_sync_s1ish() or __tlbi_sync_s1ish_hyp().

* The additional TLBI operation is chosen to have minimal impact:

  - __tlbi_sync_s1ish() uses "TLBI VALE1IS, XZR". This is only used at
    EL1 or at EL2 with {E2H,TGE}=={1,1}, where it will target an unused
    entry for the reserved ASID in the kernel's own translation regime,
    and have no adverse affect.

  - __tlbi_sync_s1ish_hyp() uses "TLBI VALE2IS, XZR". This is only used
    in hyp code, where it will target an unused entry in the hyp code's
    TTBR0 mapping, and should have no adverse effect.

* As __TLBI_0() and __TLBI_1() no longer replace each TLBI with a
  TLBI;DSB;TLBI sequence, batching TLBIs is worthwhile, and there's no
  need for arch_tlbbatch_should_defer() to consider
  ARM64_WORKAROUND_REPEAT_TLBI.

When building defconfig with GCC 15.1.0, compared to v6.19-rc1, this
patch saves ~1KiB of text, makes the vmlinux ~42KiB smaller, and makes
the resulting Image 64KiB smaller:

| [mark@lakrids:~/src/linux]% size vmlinux-*
|    text    data     bss     dec     hex filename
| 21179831        19660919         708216 41548966        279fca6 vmlinux-after
| 21181075        19660903         708216 41550194        27a0172 vmlinux-before
| [mark@lakrids:~/src/linux]% ls -l vmlinux-*
| -rwxr-xr-x 1 mark mark 157771472 Feb  4 12:05 vmlinux-after
| -rwxr-xr-x 1 mark mark 157815432 Feb  4 12:05 vmlinux-before
| [mark@lakrids:~/src/linux]% ls -l Image-*
| -rw-r--r-- 1 mark mark 41007616 Feb  4 12:05 Image-after
| -rw-r--r-- 1 mark mark 41073152 Feb  4 12:05 Image-before

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Marc Zyngier <maz@kernel.org>
Cc: Oliver Upton <oupton@kernel.org>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Will Deacon <will@kernel.org>
2026-02-25 21:37:44 +00:00
Will Deacon ed49fe5a6f KVM: arm64: Ensure TLBI uses correct VMID after changing context
When the target context passed to enter_vmid_context() matches the
current running context, the function returns early without manipulating
the registers of the stage-2 MMU. This can result in a stale VMID due to
the lack of an ISB instruction in exit_vmid_context() after writing the
VTTBR when ARM64_WORKAROUND_SPECULATIVE_AT is not enabled.

For example, with pKVM enabled:

	// Initially running in host context
	enter_vmid_context(guest);
		-> __load_stage2(guest); isb	// Writes VTCR & VTTBR
	exit_vmid_context(guest);
		-> __load_stage2(host);		// Restores VTCR & VTTBR

	enter_vmid_context(host);
		-> Returns early as we're already in host context
	tlbi vmalls12e1is	// !!! Can use the stale VMID as we
				// haven't performed context
				// synchronisation since restoring
				// VTTBR.VMID

Add an unconditional ISB instruction to exit_vmid_context() after
restoring the VTTBR. This already existed for the
ARM64_WORKAROUND_SPECULATIVE_AT path, so we can simply hoist that onto
the common path.

Cc: Marc Zyngier <maz@kernel.org>
Cc: Oliver Upton <oliver.upton@linux.dev>
Cc: Fuad Tabba <tabba@google.com>
Fixes: 58f3b0fc3b ("KVM: arm64: Support TLB invalidation in guest context")
Signed-off-by: Will Deacon <will@kernel.org>
Link: https://lore.kernel.org/r/20240814123429.20457-3-will@kernel.org
Signed-off-by: Marc Zyngier <maz@kernel.org>
2024-08-15 14:05:02 +01:00
Marc Zyngier 8540bd1b99 Merge branch kvm-arm64/pkvm-6.10 into kvmarm-master/next
* kvm-arm64/pkvm-6.10: (25 commits)
  : .
  : At last, a bunch of pKVM patches, courtesy of Fuad Tabba.
  : From the cover letter:
  :
  : "This series is a bit of a bombay-mix of patches we've been
  : carrying. There's no one overarching theme, but they do improve
  : the code by fixing existing bugs in pKVM, refactoring code to
  : make it more readable and easier to re-use for pKVM, or adding
  : functionality to the existing pKVM code upstream."
  : .
  KVM: arm64: Force injection of a data abort on NISV MMIO exit
  KVM: arm64: Restrict supported capabilities for protected VMs
  KVM: arm64: Refactor setting the return value in kvm_vm_ioctl_enable_cap()
  KVM: arm64: Document the KVM/arm64-specific calls in hypercalls.rst
  KVM: arm64: Rename firmware pseudo-register documentation file
  KVM: arm64: Reformat/beautify PTP hypercall documentation
  KVM: arm64: Clarify rationale for ZCR_EL1 value restored on guest exit
  KVM: arm64: Introduce and use predicates that check for protected VMs
  KVM: arm64: Add is_pkvm_initialized() helper
  KVM: arm64: Simplify vgic-v3 hypercalls
  KVM: arm64: Move setting the page as dirty out of the critical section
  KVM: arm64: Change kvm_handle_mmio_return() return polarity
  KVM: arm64: Fix comment for __pkvm_vcpu_init_traps()
  KVM: arm64: Prevent kmemleak from accessing .hyp.data
  KVM: arm64: Do not map the host fpsimd state to hyp in pKVM
  KVM: arm64: Rename __tlb_switch_to_{guest,host}() in VHE
  KVM: arm64: Support TLB invalidation in guest context
  KVM: arm64: Avoid BBM when changing only s/w bits in Stage-2 PTE
  KVM: arm64: Check for PTE validity when checking for executable/cacheable
  KVM: arm64: Avoid BUG-ing from the host abort path
  ...

Signed-off-by: Marc Zyngier <maz@kernel.org>
2024-05-03 11:39:52 +01:00
Will Deacon 58f3b0fc3b KVM: arm64: Support TLB invalidation in guest context
Typically, TLB invalidation of guest stage-2 mappings using nVHE is
performed by a hypercall originating from the host. For the invalidation
instruction to be effective, therefore, __tlb_switch_to_{guest,host}()
swizzle the active stage-2 context around the TLBI instruction.

With guest-to-host memory sharing and unsharing hypercalls
originating from the guest under pKVM, there is need to support
both guest and host VMID invalidations issued from guest context.

Replace the __tlb_switch_to_{guest,host}() functions with a more general
{enter,exit}_vmid_context() implementation which supports being invoked
from guest context and acts as a no-op if the target context matches the
running context.

Signed-off-by: Will Deacon <will@kernel.org>
Signed-off-by: Fuad Tabba <tabba@google.com>
Acked-by: Oliver Upton <oliver.upton@linux.dev>
Link: https://lore.kernel.org/r/20240423150538.2103045-10-tabba@google.com
Signed-off-by: Marc Zyngier <maz@kernel.org>
2024-05-01 16:47:45 +01:00
Will Deacon 0f0ff097bf KVM: arm64: Use TLBI_TTL_UNKNOWN in __kvm_tlb_flush_vmid_range()
Commit c910f2b655 ("arm64/mm: Update tlb invalidation routines for
FEAT_LPA2") updated the __tlbi_level() macro to take the target level
as an argument, with TLBI_TTL_UNKNOWN (rather than 0) indicating that
the caller cannot provide level information. Unfortunately, the two
implementations of __kvm_tlb_flush_vmid_range() were not updated and so
now ask for an level 0 invalidation if FEAT_LPA2 is implemented.

Fix the problem by passing TLBI_TTL_UNKNOWN instead of 0 as the level
argument to __flush_s2_tlb_range_op() in __kvm_tlb_flush_vmid_range().

Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Oliver Upton <oliver.upton@linux.dev>
Cc: Marc Zyngier <maz@kernel.org>
Reviewed-by: Ryan Roberts <ryan.roberts@arm.com>
Fixes: c910f2b655 ("arm64/mm: Update tlb invalidation routines for FEAT_LPA2")
Signed-off-by: Will Deacon <will@kernel.org>
Reviewed-by: Shaoqin Huang <shahuang@redhat.com>
Reviewed-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20240327124853.11206-4-will@kernel.org
Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
2024-04-01 01:30:45 -07:00
Marc Zyngier ced242ba9d KVM: arm64: Remove VPIPT I-cache handling
We have some special handling for VPIPT I-cache in critical parts
of the cache and TLB maintenance. Remove it.

Reviewed-by: Zenghui Yu <yuzenghui@huawei.com>
Reviewed-by: Anshuman Khandual <anshuman.khandual@arm.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Link: https://lore.kernel.org/r/20231204143606.1806432-2-maz@kernel.org
Signed-off-by: Will Deacon <will@kernel.org>
2023-12-05 11:38:03 +00:00
Raghavendra Rao Ananta 6354d15052 KVM: arm64: Implement __kvm_tlb_flush_vmid_range()
Define  __kvm_tlb_flush_vmid_range() (for VHE and nVHE)
to flush a range of stage-2 page-tables using IPA in one go.
If the system supports FEAT_TLBIRANGE, the following patches
would conveniently replace global TLBI such as vmalls12e1is
in the map, unmap, and dirty-logging paths with ripas2e1is
instead.

Signed-off-by: Raghavendra Rao Ananta <rananta@google.com>
Reviewed-by: Gavin Shan <gshan@redhat.com>
Reviewed-by: Shaoqin Huang <shahuang@redhat.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20230811045127.3308641-10-rananta@google.com
2023-08-17 09:40:35 +01:00
Marc Zyngier a12ab1378a KVM: arm64: Use local TLBI on permission relaxation
Broadcast TLB invalidations (TLBIs) targeting the Inner Shareable
Domain are usually less performant than their non-shareable variant.
In particular, we observed some implementations that take
millliseconds to complete parallel broadcasted TLBIs.

It's safe to use non-shareable TLBIs when relaxing permissions on a
PTE in the KVM case.  According to the ARM ARM (0487I.a) section
D8.13.1 "Using break-before-make when updating translation table
entries", permission relaxation does not need break-before-make.
Specifically, R_WHZWS states that these are the only changes that
require a break-before-make sequence: changes of memory type
(Shareability or Cacheability), address changes, or changing the block
size.

Signed-off-by: Marc Zyngier <maz@kernel.org>
Signed-off-by: Ricardo Koller <ricarkol@google.com>
Reviewed-by: Gavin Shan <gshan@redhat.com>
Link: https://lore.kernel.org/r/20230426172330.1439644-13-ricarkol@google.com
Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
2023-05-16 17:39:19 +00:00
Marc Zyngier 7e1b2329c2 KVM: arm64: nvhe: Synchronise with page table walker on TLBI
A TLBI from EL2 impacting EL1 involves messing with the EL1&0
translation regime, and the page table walker may still be
performing speculative walks.

Piggyback on the existing DSBs to always have a DSB ISH that
will synchronise all load/store operations that the PTW may
still have.

Reviewed-by: Oliver Upton <oliver.upton@linux.dev>
Signed-off-by: Marc Zyngier <maz@kernel.org>
2023-04-14 08:23:29 +01:00
Marc Zyngier 4efc0ede4f KVM: arm64: Unify stage-2 programming behind __load_stage2()
The protected mode relies on a separate helper to load the
S2 context. Move over to the __load_guest_stage2() helper
instead, and rename it to __load_stage2() to present a unified
interface.

Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Jade Alglave <jade.alglave@arm.com>
Cc: Shameer Kolothum <shameerali.kolothum.thodi@huawei.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Signed-off-by: Will Deacon <will@kernel.org>
Link: https://lore.kernel.org/r/20210806113109.2475-5-will@kernel.org
2021-08-20 09:11:28 +01:00
Marc Zyngier 923a547d71 KVM: arm64: Move kern_hyp_va() usage in __load_guest_stage2() into the callers
It is a bit awkward to use kern_hyp_va() in __load_guest_stage2(),
specially as the helper is shared between VHE and nVHE.

Instead, move the use of kern_hyp_va() in the nVHE code, and
pass a pointer to the kvm->arch structure instead. Although
this may look a bit awkward, it allows for some further simplification.

Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Jade Alglave <jade.alglave@arm.com>
Cc: Shameer Kolothum <shameerali.kolothum.thodi@huawei.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Signed-off-by: Will Deacon <will@kernel.org>
Link: https://lore.kernel.org/r/20210806113109.2475-4-will@kernel.org
2021-08-20 09:03:42 +01:00
Fuad Tabba fade9c2c6e arm64: Rename arm64-internal cache maintenance functions
Although naming across the codebase isn't that consistent, it
tends to follow certain patterns. Moreover, the term "flush"
isn't defined in the Arm Architecture reference manual, and might
be interpreted to mean clean, invalidate, or both for a cache.

Rename arm64-internal functions to make the naming internally
consistent, as well as making it consistent with the Arm ARM, by
specifying whether it applies to the instruction, data, or both
caches, whether the operation is a clean, invalidate, or both.
Also specify which point the operation applies to, i.e., to the
point of unification (PoU), coherency (PoC), or persistence
(PoP).

This commit applies the following sed transformation to all files
under arch/arm64:

"s/\b__flush_cache_range\b/caches_clean_inval_pou_macro/g;"\
"s/\b__flush_icache_range\b/caches_clean_inval_pou/g;"\
"s/\binvalidate_icache_range\b/icache_inval_pou/g;"\
"s/\b__flush_dcache_area\b/dcache_clean_inval_poc/g;"\
"s/\b__inval_dcache_area\b/dcache_inval_poc/g;"\
"s/__clean_dcache_area_poc\b/dcache_clean_poc/g;"\
"s/\b__clean_dcache_area_pop\b/dcache_clean_pop/g;"\
"s/\b__clean_dcache_area_pou\b/dcache_clean_pou/g;"\
"s/\b__flush_cache_user_range\b/caches_clean_inval_user_pou/g;"\
"s/\b__flush_icache_all\b/icache_inval_all_pou/g;"

Note that __clean_dcache_area_poc is deliberately missing a word
boundary check at the beginning in order to match the efistub
symbols in image-vars.h.

Also note that, despite its name, __flush_icache_range operates
on both instruction and data caches. The name change here
reflects that.

No functional change intended.

Acked-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Fuad Tabba <tabba@google.com>
Reviewed-by: Ard Biesheuvel <ardb@kernel.org>
Link: https://lore.kernel.org/r/20210524083001.2586635-19-tabba@google.com
Signed-off-by: Will Deacon <will@kernel.org>
2021-05-25 19:27:49 +01:00
Quentin Perret 1025c8c0c6 KVM: arm64: Wrap the host with a stage 2
When KVM runs in protected nVHE mode, make use of a stage 2 page-table
to give the hypervisor some control over the host memory accesses. The
host stage 2 is created lazily using large block mappings if possible,
and will default to page mappings in absence of a better solution.

>From this point on, memory accesses from the host to protected memory
regions (e.g. not 'owned' by the host) are fatal and lead to hyp_panic().

Acked-by: Will Deacon <will@kernel.org>
Signed-off-by: Quentin Perret <qperret@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20210319100146.1149909-36-qperret@google.com
2021-03-19 12:02:18 +00:00
Marc Zyngier 01dc9262ff KVM: arm64: Ensure I-cache isolation between vcpus of a same VM
It recently became apparent that the ARMv8 architecture has interesting
rules regarding attributes being used when fetching instructions
if the MMU is off at Stage-1.

In this situation, the CPU is allowed to fetch from the PoC and
allocate into the I-cache (unless the memory is mapped with
the XN attribute at Stage-2).

If we transpose this to vcpus sharing a single physical CPU,
it is possible for a vcpu running with its MMU off to influence
another vcpu running with its MMU on, as the latter is expected to
fetch from the PoU (and self-patching code doesn't flush below that
level).

In order to solve this, reuse the vcpu-private TLB invalidation
code to apply the same policy to the I-cache, nuking it every time
the vcpu runs on a physical CPU that ran another vcpu of the same
VM in the past.

This involve renaming __kvm_tlb_flush_local_vmid() to
__kvm_flush_cpu_context(), and inserting a local i-cache invalidation
there.

Cc: stable@vger.kernel.org
Signed-off-by: Marc Zyngier <maz@kernel.org>
Acked-by: Will Deacon <will@kernel.org>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Link: https://lore.kernel.org/r/20210303164505.68492-1-maz@kernel.org
2021-03-09 17:58:56 +00:00
Paolo Bonzini 699116c45e KVM/arm64 fixes for 5.10, take #1
- Force PTE mapping on device pages provided via VFIO
 - Fix detection of cacheable mapping at S2
 - Fallback to PMD/PTE mappings for composite huge pages
 - Fix accounting of Stage-2 PGD allocation
 - Fix AArch32 handling of some of the debug registers
 - Simplify host HYP entry
 - Fix stray pointer conversion on nVHE TLB invalidation
 - Fix initialization of the nVHE code
 - Simplify handling of capabilities exposed to HYP
 - Nuke VCPUs caught using a forbidden AArch32 EL0
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Merge tag 'kvmarm-fixes-5.10-1' of git://git.kernel.org/pub/scm/linux/kernel/git/kvmarm/kvmarm into HEAD

KVM/arm64 fixes for 5.10, take #1

- Force PTE mapping on device pages provided via VFIO
- Fix detection of cacheable mapping at S2
- Fallback to PMD/PTE mappings for composite huge pages
- Fix accounting of Stage-2 PGD allocation
- Fix AArch32 handling of some of the debug registers
- Simplify host HYP entry
- Fix stray pointer conversion on nVHE TLB invalidation
- Fix initialization of the nVHE code
- Simplify handling of capabilities exposed to HYP
- Nuke VCPUs caught using a forbidden AArch32 EL0
2020-10-30 13:25:09 -04:00
Marc Zyngier b6d6db4de8 KVM: arm64: Remove leftover kern_hyp_va() in nVHE TLB invalidation
The new calling convention says that pointers coming from the SMCCC
interface are turned into their HYP version in the host HVC handler.
However, there is still a stray kern_hyp_va() in the TLB invalidation
code, which could result in a corrupted pointer.

Drop the spurious conversion.

Fixes: a071261d93 ("KVM: arm64: nVHE: Fix pointers during SMCCC convertion")
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20201026095116.72051-3-maz@kernel.org
2020-10-29 19:49:03 +00:00
Paolo Bonzini c0623f5e5d Merge branch 'kvm-fixes' into 'next'
Pick up bugfixes from 5.9, otherwise various tests fail.
2020-10-21 18:05:58 -04:00
Marc Zyngier 452d622279 KVM: arm64: Restore missing ISB on nVHE __tlb_switch_to_guest
Commit a0e50aa3f4 ("KVM: arm64: Factor out stage 2 page table
data from struct kvm") dropped the ISB after __load_guest_stage2(),
only leaving the one that is required when the speculative AT
workaround is in effect.

As Andrew points it: "This alternative is 'backwards' to avoid a
double ISB as there is one in __load_guest_stage2 when the workaround
is active."

Restore the missing ISB, conditionned on the AT workaround not being
active.

Fixes: a0e50aa3f4 ("KVM: arm64: Factor out stage 2 page table data from struct kvm")
Reported-by: Andrew Scull <ascull@google.com>
Reported-by: Thomas Tai <thomas.tai@oracle.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
2020-10-01 09:53:45 +01:00
Andrew Scull a071261d93 KVM: arm64: nVHE: Fix pointers during SMCCC convertion
The host need not concern itself with the pointer differences for the
hyp interfaces that are shared between VHE and nVHE so leave it to the
hyp to handle.

As the SMCCC function IDs are converted into function calls, it is a
suitable place to also convert any pointer arguments into hyp pointers.
This, additionally, eases the reuse of the handlers in different
contexts.

Signed-off-by: Andrew Scull <ascull@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20200915104643.2543892-20-ascull@google.com
2020-09-15 18:39:04 +01:00
Marc Zyngier efaa5b93af KVM: arm64: Use TTL hint in when invalidating stage-2 translations
Since we often have a precise idea of the level we're dealing with
when invalidating TLBs, we can provide it to as a hint to our
invalidation helper.

Reviewed-by: James Morse <james.morse@arm.com>
Reviewed-by: Alexandru Elisei <alexandru.elisei@arm.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
2020-07-07 09:28:37 +01:00
Christoffer Dall a0e50aa3f4 KVM: arm64: Factor out stage 2 page table data from struct kvm
As we are about to reuse our stage 2 page table manipulation code for
shadow stage 2 page tables in the context of nested virtualization, we
are going to manage multiple stage 2 page tables for a single VM.

This requires some pretty invasive changes to our data structures,
which moves the vmid and pgd pointers into a separate structure and
change pretty much all of our mmu code to operate on this structure
instead.

The new structure is called struct kvm_s2_mmu.

There is no intended functional change by this patch alone.

Reviewed-by: James Morse <james.morse@arm.com>
Reviewed-by: Alexandru Elisei <alexandru.elisei@arm.com>
[Designed data structure layout in collaboration]
Signed-off-by: Christoffer Dall <christoffer.dall@arm.com>
Co-developed-by: Marc Zyngier <maz@kernel.org>
[maz: Moved the last_vcpu_ran down to the S2 MMU structure as well]
Signed-off-by: Marc Zyngier <maz@kernel.org>
2020-07-07 09:28:37 +01:00
David Brazdil c50cb04303 KVM: arm64: Remove __hyp_text macro, use build rules instead
With nVHE code now fully separated from the rest of the kernel, the effects of
the __hyp_text macro (which had to be applied on all nVHE code) can be
achieved with build rules instead. The macro used to:
  (a) move code to .hyp.text ELF section, now done by renaming .text using
      `objcopy`, and
  (b) `notrace` and `__noscs` would negate effects of CC_FLAGS_FTRACE and
      CC_FLAGS_SCS, respectivelly, now those flags are  erased from
      KBUILD_CFLAGS (same way as in EFI stub).

Note that by removing __hyp_text from code shared with VHE, all VHE code is now
compiled into .text and without `notrace` and `__noscs`.

Use of '.pushsection .hyp.text' removed from assembly files as this is now also
covered by the build rules.

For MAINTAINERS: if needed to re-run, uses of macro were removed with the
following command. Formatting was fixed up manually.

  find arch/arm64/kvm/hyp -type f -name '*.c' -o -name '*.h' \
       -exec sed -i 's/ __hyp_text//g' {} +

Signed-off-by: David Brazdil <dbrazdil@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20200625131420.71444-15-dbrazdil@google.com
2020-07-05 18:38:45 +01:00
David Brazdil e03fa29164 KVM: arm64: Duplicate hyp/tlb.c for VHE/nVHE
tlb.c contains code for flushing the TLB, with code shared between VHE/nVHE.
Because common code is small, duplicate tlb.c and specialize each copy for
VHE/nVHE.

Signed-off-by: David Brazdil <dbrazdil@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20200625131420.71444-9-dbrazdil@google.com
2020-07-05 18:38:17 +01:00