<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux-dev/arch/x86/include/uapi/asm, branch master</title>
<subtitle>Linux kernel development work - see feature branches</subtitle>
<id>https://git.zx2c4.com/linux-dev/atom/arch/x86/include/uapi/asm?h=master</id>
<link rel='self' href='https://git.zx2c4.com/linux-dev/atom/arch/x86/include/uapi/asm?h=master'/>
<link rel='alternate' type='text/html' href='https://git.zx2c4.com/linux-dev/'/>
<updated>2022-08-05T17:47:40Z</updated>
<entry>
<title>Merge tag 'x86_sgx_for_v6.0-2022-08-03.1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip</title>
<updated>2022-08-05T17:47:40Z</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2022-08-05T17:47:40Z</published>
<link rel='alternate' type='text/html' href='https://git.zx2c4.com/linux-dev/commit/?id=9e2f40233670c70c25e0681cb66d50d1e2742829'/>
<id>urn:sha1:9e2f40233670c70c25e0681cb66d50d1e2742829</id>
<content type='text'>
Pull x86 SGX updates from Dave Hansen:
 "A set of x86/sgx changes focused on implementing the "SGX2" features,
  plus a minor cleanup:

   - SGX2 ISA support which makes enclave memory management much more
     dynamic. For instance, enclaves can now change enclave page
     permissions on the fly.

   - Removal of an unused structure member"

* tag 'x86_sgx_for_v6.0-2022-08-03.1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (32 commits)
  x86/sgx: Drop 'page_index' from sgx_backing
  selftests/sgx: Page removal stress test
  selftests/sgx: Test reclaiming of untouched page
  selftests/sgx: Test invalid access to removed enclave page
  selftests/sgx: Test faulty enclave behavior
  selftests/sgx: Test complete changing of page type flow
  selftests/sgx: Introduce TCS initialization enclave operation
  selftests/sgx: Introduce dynamic entry point
  selftests/sgx: Test two different SGX2 EAUG flows
  selftests/sgx: Add test for TCS page permission changes
  selftests/sgx: Add test for EPCM permission changes
  Documentation/x86: Introduce enclave runtime management section
  x86/sgx: Free up EPC pages directly to support large page ranges
  x86/sgx: Support complete page removal
  x86/sgx: Support modifying SGX page type
  x86/sgx: Tighten accessible memory range after enclave initialization
  x86/sgx: Support adding of pages to an initialized enclave
  x86/sgx: Support restricting of enclave page permissions
  x86/sgx: Support VA page allocation without reclaiming
  x86/sgx: Export sgx_encl_page_alloc()
  ...
</content>
</entry>
<entry>
<title>Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm</title>
<updated>2022-08-04T21:59:54Z</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2022-08-04T21:59:54Z</published>
<link rel='alternate' type='text/html' href='https://git.zx2c4.com/linux-dev/commit/?id=7c5c3a6177fa9646884114fc7f2e970b0bc50dc9'/>
<id>urn:sha1:7c5c3a6177fa9646884114fc7f2e970b0bc50dc9</id>
<content type='text'>
Pull kvm updates from Paolo Bonzini:
 "Quite a large pull request due to a selftest API overhaul and some
  patches that had come in too late for 5.19.

  ARM:

   - Unwinder implementations for both nVHE modes (classic and
     protected), complete with an overflow stack

   - Rework of the sysreg access from userspace, with a complete rewrite
     of the vgic-v3 view to allign with the rest of the infrastructure

   - Disagregation of the vcpu flags in separate sets to better track
     their use model.

   - A fix for the GICv2-on-v3 selftest

   - A small set of cosmetic fixes

  RISC-V:

   - Track ISA extensions used by Guest using bitmap

   - Added system instruction emulation framework

   - Added CSR emulation framework

   - Added gfp_custom flag in struct kvm_mmu_memory_cache

   - Added G-stage ioremap() and iounmap() functions

   - Added support for Svpbmt inside Guest

  s390:

   - add an interface to provide a hypervisor dump for secure guests

   - improve selftests to use TAP interface

   - enable interpretive execution of zPCI instructions (for PCI
     passthrough)

   - First part of deferred teardown

   - CPU Topology

   - PV attestation

   - Minor fixes

  x86:

   - Permit guests to ignore single-bit ECC errors

   - Intel IPI virtualization

   - Allow getting/setting pending triple fault with
     KVM_GET/SET_VCPU_EVENTS

   - PEBS virtualization

   - Simplify PMU emulation by just using PERF_TYPE_RAW events

   - More accurate event reinjection on SVM (avoid retrying
     instructions)

   - Allow getting/setting the state of the speaker port data bit

   - Refuse starting the kvm-intel module if VM-Entry/VM-Exit controls
     are inconsistent

   - "Notify" VM exit (detect microarchitectural hangs) for Intel

   - Use try_cmpxchg64 instead of cmpxchg64

   - Ignore benign host accesses to PMU MSRs when PMU is disabled

   - Allow disabling KVM's "MONITOR/MWAIT are NOPs!" behavior

   - Allow NX huge page mitigation to be disabled on a per-vm basis

   - Port eager page splitting to shadow MMU as well

   - Enable CMCI capability by default and handle injected UCNA errors

   - Expose pid of vcpu threads in debugfs

   - x2AVIC support for AMD

   - cleanup PIO emulation

   - Fixes for LLDT/LTR emulation

   - Don't require refcounted "struct page" to create huge SPTEs

   - Miscellaneous cleanups:
      - MCE MSR emulation
      - Use separate namespaces for guest PTEs and shadow PTEs bitmasks
      - PIO emulation
      - Reorganize rmap API, mostly around rmap destruction
      - Do not workaround very old KVM bugs for L0 that runs with nesting enabled
      - new selftests API for CPUID

  Generic:

   - Fix races in gfn-&gt;pfn cache refresh; do not pin pages tracked by
     the cache

   - new selftests API using struct kvm_vcpu instead of a (vm, id)
     tuple"

* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (606 commits)
  selftests: kvm: set rax before vmcall
  selftests: KVM: Add exponent check for boolean stats
  selftests: KVM: Provide descriptive assertions in kvm_binary_stats_test
  selftests: KVM: Check stat name before other fields
  KVM: x86/mmu: remove unused variable
  RISC-V: KVM: Add support for Svpbmt inside Guest/VM
  RISC-V: KVM: Use PAGE_KERNEL_IO in kvm_riscv_gstage_ioremap()
  RISC-V: KVM: Add G-stage ioremap() and iounmap() functions
  KVM: Add gfp_custom flag in struct kvm_mmu_memory_cache
  RISC-V: KVM: Add extensible CSR emulation framework
  RISC-V: KVM: Add extensible system instruction emulation framework
  RISC-V: KVM: Factor-out instruction emulation into separate sources
  RISC-V: KVM: move preempt_disable() call in kvm_arch_vcpu_ioctl_run
  RISC-V: KVM: Make kvm_riscv_guest_timer_init a void function
  RISC-V: KVM: Fix variable spelling mistake
  RISC-V: KVM: Improve ISA extension by using a bitmap
  KVM, x86/mmu: Fix the comment around kvm_tdp_mmu_zap_leafs()
  KVM: SVM: Dump Virtual Machine Save Area (VMSA) to klog
  KVM: x86/mmu: Treat NX as a valid SPTE bit for NPT
  KVM: x86: Do not block APIC write for non ICR registers
  ...
</content>
</entry>
<entry>
<title>Merge tag 'flexible-array-transformations-UAPI-6.0-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gustavoars/linux</title>
<updated>2022-08-03T02:50:47Z</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2022-08-03T02:50:47Z</published>
<link rel='alternate' type='text/html' href='https://git.zx2c4.com/linux-dev/commit/?id=e2b542100719a93f8cdf6d90185410d38a57a4c1'/>
<id>urn:sha1:e2b542100719a93f8cdf6d90185410d38a57a4c1</id>
<content type='text'>
Pull uapi flexible array update from Gustavo Silva:
 "A treewide patch that replaces zero-length arrays with flexible-array
  members in UAPI. This has been baking in linux-next for 5 weeks now.

  '-fstrict-flex-arrays=3' is coming and we need to land these changes
  to prevent issues like these in the short future:

    fs/minix/dir.c:337:3: warning: 'strcpy' will always overflow; destination buffer has size 0, but the source string has length 2 (including NUL byte) [-Wfortify-source]
		strcpy(de3-&gt;name, ".");
		^

  Since these are all [0] to [] changes, the risk to UAPI is nearly
  zero. If this breaks anything, we can use a union with a new member
  name"

Link: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=101836

* tag 'flexible-array-transformations-UAPI-6.0-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gustavoars/linux:
  treewide: uapi: Replace zero-length arrays with flexible-array members
</content>
</entry>
<entry>
<title>Merge remote-tracking branch 'kvm/next' into kvm-next-5.20</title>
<updated>2022-08-01T07:21:00Z</updated>
<author>
<name>Paolo Bonzini</name>
<email>pbonzini@redhat.com</email>
</author>
<published>2022-07-29T13:46:01Z</published>
<link rel='alternate' type='text/html' href='https://git.zx2c4.com/linux-dev/commit/?id=63f4b210414b65aa3103c54369cacbd0b1bdf02f'/>
<id>urn:sha1:63f4b210414b65aa3103c54369cacbd0b1bdf02f</id>
<content type='text'>
KVM/s390, KVM/x86 and common infrastructure changes for 5.20

x86:

* Permit guests to ignore single-bit ECC errors

* Fix races in gfn-&gt;pfn cache refresh; do not pin pages tracked by the cache

* Intel IPI virtualization

* Allow getting/setting pending triple fault with KVM_GET/SET_VCPU_EVENTS

* PEBS virtualization

* Simplify PMU emulation by just using PERF_TYPE_RAW events

* More accurate event reinjection on SVM (avoid retrying instructions)

* Allow getting/setting the state of the speaker port data bit

* Refuse starting the kvm-intel module if VM-Entry/VM-Exit controls are inconsistent

* "Notify" VM exit (detect microarchitectural hangs) for Intel

* Cleanups for MCE MSR emulation

s390:

* add an interface to provide a hypervisor dump for secure guests

* improve selftests to use TAP interface

* enable interpretive execution of zPCI instructions (for PCI passthrough)

* First part of deferred teardown

* CPU Topology

* PV attestation

* Minor fixes

Generic:

* new selftests API using struct kvm_vcpu instead of a (vm, id) tuple

x86:

* Use try_cmpxchg64 instead of cmpxchg64

* Bugfixes

* Ignore benign host accesses to PMU MSRs when PMU is disabled

* Allow disabling KVM's "MONITOR/MWAIT are NOPs!" behavior

* x86/MMU: Allow NX huge pages to be disabled on a per-vm basis

* Port eager page splitting to shadow MMU as well

* Enable CMCI capability by default and handle injected UCNA errors

* Expose pid of vcpu threads in debugfs

* x2AVIC support for AMD

* cleanup PIO emulation

* Fixes for LLDT/LTR emulation

* Don't require refcounted "struct page" to create huge SPTEs

x86 cleanups:

* Use separate namespaces for guest PTEs and shadow PTEs bitmasks

* PIO emulation

* Reorganize rmap API, mostly around rmap destruction

* Do not workaround very old KVM bugs for L0 that runs with nesting enabled

* new selftests API for CPUID
</content>
</entry>
<entry>
<title>KVM: x86: Tweak name of MONITOR/MWAIT #UD quirk to make it #UD specific</title>
<updated>2022-07-14T01:14:05Z</updated>
<author>
<name>Sean Christopherson</name>
<email>seanjc@google.com</email>
</author>
<published>2022-07-11T22:57:53Z</published>
<link rel='alternate' type='text/html' href='https://git.zx2c4.com/linux-dev/commit/?id=43bb9e000ea4c62154c01844771fea25b8b83520'/>
<id>urn:sha1:43bb9e000ea4c62154c01844771fea25b8b83520</id>
<content type='text'>
Add a "UD" clause to KVM_X86_QUIRK_MWAIT_NEVER_FAULTS to make it clear
that the quirk only controls the #UD behavior of MONITOR/MWAIT.  KVM
doesn't currently enforce fault checks when MONITOR/MWAIT are supported,
but that could change in the future.  SVM also has a virtualization hole
in that it checks all faults before intercepts, and so "never faults" is
already a lie when running on SVM.

Fixes: bfbcc81bb82c ("KVM: x86: Add a quirk for KVM's "MONITOR/MWAIT are NOPs!" behavior")
Signed-off-by: Sean Christopherson &lt;seanjc@google.com&gt;
Link: https://lore.kernel.org/r/20220711225753.1073989-4-seanjc@google.com
</content>
</entry>
<entry>
<title>x86/setup: Use rng seeds from setup_data</title>
<updated>2022-07-11T07:59:31Z</updated>
<author>
<name>Jason A. Donenfeld</name>
<email>Jason@zx2c4.com</email>
</author>
<published>2022-07-10T17:29:21Z</published>
<link rel='alternate' type='text/html' href='https://git.zx2c4.com/linux-dev/commit/?id=68b8e9713c8ec90af93c16e1de51cca18cefdb56'/>
<id>urn:sha1:68b8e9713c8ec90af93c16e1de51cca18cefdb56</id>
<content type='text'>
Currently, the only way x86 can get an early boot RNG seed is via EFI,
which is generally always used now for physical machines, but is very
rarely used in VMs, especially VMs that are optimized for starting
"instantaneously", such as Firecracker's MicroVM. For tiny fast booting
VMs, EFI is not something you generally need or want.

Rather, the image loader or firmware should be able to pass a single
random seed, exactly as device tree platforms do with the "rng-seed"
property. Additionally, this is something that bootloaders can append,
with their own seed file management, which is something every other
major OS ecosystem has that Linux does not (yet).

Add SETUP_RNG_SEED, similar to the other eight setup_data entries that
are parsed at boot. It also takes care to zero out the seed immediately
after using, in order to retain forward secrecy. This all takes about 7
trivial lines of code.

Then, on kexec_file_load(), a new fresh seed is generated and passed to
the next kernel, just as is done on device tree architectures when
using kexec. And, importantly, I've tested that QEMU is able to properly
pass SETUP_RNG_SEED as well, making this work for every step of the way.
This code too is pretty straight forward.

Together these measures ensure that VMs and nested kexec()'d kernels
always receive a proper boot time RNG seed at the earliest possible
stage from their parents:

   - Host [already has strongly initialized RNG]
     - QEMU [passes fresh seed in SETUP_RNG_SEED field]
       - Linux [uses parent's seed and gathers entropy of its own]
         - kexec [passes this in SETUP_RNG_SEED field]
           - Linux [uses parent's seed and gathers entropy of its own]
             - kexec [passes this in SETUP_RNG_SEED field]
               - Linux [uses parent's seed and gathers entropy of its own]
                 - kexec [passes this in SETUP_RNG_SEED field]
		   - ...

I've verified in several scenarios that this works quite well from a
host kernel to QEMU and down inwards, mixing and matching loaders, with
every layer providing a seed to the next.

  [ bp: Massage commit message. ]

Signed-off-by: Jason A. Donenfeld &lt;Jason@zx2c4.com&gt;
Signed-off-by: Borislav Petkov &lt;bp@suse.de&gt;
Acked-by: H. Peter Anvin (Intel) &lt;hpa@zytor.com&gt;
Link: https://lore.kernel.org/r/20220630113300.1892799-1-Jason@zx2c4.com
</content>
</entry>
<entry>
<title>Merge tag 'v5.19-rc6' into tip:x86/kdump</title>
<updated>2022-07-11T07:58:01Z</updated>
<author>
<name>Borislav Petkov</name>
<email>bp@suse.de</email>
</author>
<published>2022-07-11T07:58:01Z</published>
<link rel='alternate' type='text/html' href='https://git.zx2c4.com/linux-dev/commit/?id=5a88c48f4146de2c8c2ed7ddcaa76f898869f3a3'/>
<id>urn:sha1:5a88c48f4146de2c8c2ed7ddcaa76f898869f3a3</id>
<content type='text'>
Merge rc6 to pick up dependent changes to the bootparam UAPI header.

Signed-off-by: Borislav Petkov &lt;bp@suse.de&gt;
</content>
</entry>
<entry>
<title>x86/boot: Fix the setup data types max limit</title>
<updated>2022-07-10T09:17:40Z</updated>
<author>
<name>Borislav Petkov</name>
<email>bp@suse.de</email>
</author>
<published>2022-07-10T09:15:47Z</published>
<link rel='alternate' type='text/html' href='https://git.zx2c4.com/linux-dev/commit/?id=cb8a4beac39b90cd60abbf9fd639a3357274e469'/>
<id>urn:sha1:cb8a4beac39b90cd60abbf9fd639a3357274e469</id>
<content type='text'>
Commit in Fixes forgot to change the SETUP_TYPE_MAX definition which
contains the highest valid setup data type.

Correct that.

Fixes: 5ea98e01ab52 ("x86/boot: Add Confidential Computing type to setup_data")
Signed-off-by: Borislav Petkov &lt;bp@suse.de&gt;
Link: https://lore.kernel.org/r/ddba81dd-cc92-699c-5274-785396a17fb5@zytor.com
</content>
</entry>
<entry>
<title>x86/sgx: Support complete page removal</title>
<updated>2022-07-07T17:13:03Z</updated>
<author>
<name>Reinette Chatre</name>
<email>reinette.chatre@intel.com</email>
</author>
<published>2022-05-10T18:08:55Z</published>
<link rel='alternate' type='text/html' href='https://git.zx2c4.com/linux-dev/commit/?id=9849bb27152c18e8531424c0a8ef5f51ece40aea'/>
<id>urn:sha1:9849bb27152c18e8531424c0a8ef5f51ece40aea</id>
<content type='text'>
The SGX2 page removal flow was introduced in previous patch and is
as follows:
1) Change the type of the pages to be removed to SGX_PAGE_TYPE_TRIM
   using the ioctl() SGX_IOC_ENCLAVE_MODIFY_TYPES introduced in
   previous patch.
2) Approve the page removal by running ENCLU[EACCEPT] from within
   the enclave.
3) Initiate actual page removal using the ioctl()
   SGX_IOC_ENCLAVE_REMOVE_PAGES introduced here.

Support the final step of the SGX2 page removal flow with ioctl()
SGX_IOC_ENCLAVE_REMOVE_PAGES. With this ioctl() the user specifies
a page range that should be removed. All pages in the provided
range should have the SGX_PAGE_TYPE_TRIM page type and the request
will fail with EPERM (Operation not permitted) if a page that does
not have the correct type is encountered. Page removal can fail
on any page within the provided range. Support partial success by
returning the number of pages that were successfully removed.

Since actual page removal will succeed even if ENCLU[EACCEPT] was not
run from within the enclave the ENCLU[EMODPR] instruction with RWX
permissions is used as a no-op mechanism to ensure ENCLU[EACCEPT] was
successfully run from within the enclave before the enclave page is
removed.

If the user omits running SGX_IOC_ENCLAVE_REMOVE_PAGES the pages will
still be removed when the enclave is unloaded.

Signed-off-by: Reinette Chatre &lt;reinette.chatre@intel.com&gt;
Signed-off-by: Dave Hansen &lt;dave.hansen@linux.intel.com&gt;
Reviewed-by: Jarkko Sakkinen &lt;jarkko@kernel.org&gt;
Tested-by: Haitao Huang &lt;haitao.huang@intel.com&gt;
Tested-by: Vijay Dhanraj &lt;vijay.dhanraj@intel.com&gt;
Tested-by: Jarkko Sakkinen &lt;jarkko@kernel.org&gt;
Link: https://lkml.kernel.org/r/b75ee93e96774e38bb44a24b8e9bbfb67b08b51b.1652137848.git.reinette.chatre@intel.com
</content>
</entry>
<entry>
<title>x86/sgx: Support modifying SGX page type</title>
<updated>2022-07-07T17:13:03Z</updated>
<author>
<name>Reinette Chatre</name>
<email>reinette.chatre@intel.com</email>
</author>
<published>2022-05-10T18:08:54Z</published>
<link rel='alternate' type='text/html' href='https://git.zx2c4.com/linux-dev/commit/?id=45d546b8c109d69f6659d58b2ace005b2f07f557'/>
<id>urn:sha1:45d546b8c109d69f6659d58b2ace005b2f07f557</id>
<content type='text'>
Every enclave contains one or more Thread Control Structures (TCS). The
TCS contains meta-data used by the hardware to save and restore thread
specific information when entering/exiting the enclave. With SGX1 an
enclave needs to be created with enough TCSs to support the largest
number of threads expecting to use the enclave and enough enclave pages
to meet all its anticipated memory demands. In SGX1 all pages remain in
the enclave until the enclave is unloaded.

SGX2 introduces a new function, ENCLS[EMODT], that is used to change
the type of an enclave page from a regular (SGX_PAGE_TYPE_REG) enclave
page to a TCS (SGX_PAGE_TYPE_TCS) page or change the type from a
regular (SGX_PAGE_TYPE_REG) or TCS (SGX_PAGE_TYPE_TCS)
page to a trimmed (SGX_PAGE_TYPE_TRIM) page (setting it up for later
removal).

With the existing support of dynamically adding regular enclave pages
to an initialized enclave and changing the page type to TCS it is
possible to dynamically increase the number of threads supported by an
enclave.

Changing the enclave page type to SGX_PAGE_TYPE_TRIM is the first step
of dynamically removing pages from an initialized enclave. The complete
page removal flow is:
1) Change the type of the pages to be removed to SGX_PAGE_TYPE_TRIM
   using the SGX_IOC_ENCLAVE_MODIFY_TYPES ioctl() introduced here.
2) Approve the page removal by running ENCLU[EACCEPT] from within
   the enclave.
3) Initiate actual page removal using the ioctl() introduced in the
   following patch.

Add ioctl() SGX_IOC_ENCLAVE_MODIFY_TYPES to support changing SGX
enclave page types within an initialized enclave. With
SGX_IOC_ENCLAVE_MODIFY_TYPES the user specifies a page range and the
enclave page type to be applied to all pages in the provided range.
The ioctl() itself can return an error code based on failures
encountered by the kernel. It is also possible for SGX specific
failures to be encountered.  Add a result output parameter to
communicate the SGX return code. It is possible for the enclave page
type change request to fail on any page within the provided range.
Support partial success by returning the number of pages that were
successfully changed.

After the page type is changed the page continues to be accessible
from the kernel perspective with page table entries and internal
state. The page may be moved to swap. Any access until ENCLU[EACCEPT]
will encounter a page fault with SGX flag set in error code.

Signed-off-by: Reinette Chatre &lt;reinette.chatre@intel.com&gt;
Signed-off-by: Dave Hansen &lt;dave.hansen@linux.intel.com&gt;
Reviewed-by: Jarkko Sakkinen &lt;jarkko@kernel.org&gt;
Tested-by: Jarkko Sakkinen &lt;jarkko@kernel.org&gt;
Tested-by: Haitao Huang &lt;haitao.huang@intel.com&gt;
Tested-by: Vijay Dhanraj &lt;vijay.dhanraj@intel.com&gt;
Link: https://lkml.kernel.org/r/babe39318c5bf16fc65fbfb38896cdee72161575.1652137848.git.reinette.chatre@intel.com
</content>
</entry>
</feed>
