Commit graph

17 commits

Author SHA1 Message Date
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
Renamed from arch/arm64/kvm/hyp/tlb.c (Browse further)