Fix a sparse warning in sev_guest_probe() where the wrong argument type is
provided to iounmap().

Fixes: fce96cf04430 ("virt: Add SEV-SNP guest driver")
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lore.kernel.org/r/202207150617.jqwQ0Rpz-lkp@intel.com

Pull AMD SEV-SNP support from Borislav Petkov:
 "The third AMD confidential computing feature called Secure Nested
  Paging.

  Add to confidential guests the necessary memory integrity protection
  against malicious hypervisor-based attacks like data replay, memory
  remapping and others, thus achieving a stronger isolation from the
  hypervisor.

  At the core of the functionality is a new structure called a reverse
  map table (RMP) with which the guest has a say in which pages get
  assigned to it and gets notified when a page which it owns, gets
  accessed/modified under the covers so that the guest can take an
  appropriate action.

  In addition, add support for the whole machinery needed to launch a
  SNP guest, details of which is properly explained in each patch.

  And last but not least, the series refactors and improves parts of the
  previous SEV support so that the new code is accomodated properly and
  not just bolted on"

* tag 'x86_sev_for_v5.19_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (60 commits)
  x86/entry: Fixup objtool/ibt validation
  x86/sev: Mark the code returning to user space as syscall gap
  x86/sev: Annotate stack change in the #VC handler
  x86/sev: Remove duplicated assignment to variable info
  x86/sev: Fix address space sparse warning
  x86/sev: Get the AP jump table address from secrets page
  x86/sev: Add missing __init annotations to SEV init routines
  virt: sevguest: Rename the sevguest dir and files to sev-guest
  virt: sevguest: Change driver name to reflect generic SEV support
  x86/boot: Put globals that are accessed early into the .data section
  x86/boot: Add an efi.h header for the decompressor
  virt: sevguest: Fix bool function returning negative value
  virt: sevguest: Fix return value check in alloc_shared_pages()
  x86/sev-es: Replace open-coded hlt-loop with sev_es_terminate()
  virt: sevguest: Add documentation for SEV-SNP CPUID Enforcement
  virt: sevguest: Add support to get extended report
  virt: sevguest: Add support to derive key
  virt: Add SEV-SNP guest driver
  x86/sev: Register SEV-SNP guest request platform device
  x86/sev: Provide support for SNP guest request NAEs
  ...

The GHCB specification section 2.7 states that when SEV-SNP is enabled,
a guest should not rely on the hypervisor to provide the address of the
AP jump table. Instead, if a guest BIOS wants to provide an AP jump
table, it should record the address in the SNP secrets page so the guest
operating system can obtain it directly from there.

Fix this on the guest kernel side by having SNP guests use the AP jump
table address published in the secrets page rather than issuing a GHCB
request to get it.

  [ mroth:
    - Improve error handling when ioremap()/memremap() return NULL
    - Don't mix function calls with declarations
    - Add missing __init
    - Tweak commit message ]

Fixes: 0afb6b660a6b ("x86/sev: Use SEV-SNP AP creation to start secondary CPUs")
Signed-off-by: Brijesh Singh <brijesh.singh@amd.com>
Signed-off-by: Michael Roth <michael.roth@amd.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lore.kernel.org/r/20220422135624.114172-3-michael.roth@amd.com

Rename the drivers/virt/coco/sevguest directory and files to sev-guest
so as to match the driver name.

  [ bp: Rename Documentation/virt/coco/sevguest.rst too, as reported by sfr:
    https://lore.kernel.org/r/20220427101059.3bf55262@canb.auug.org.au ]

Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lore.kernel.org/r/2f5c9cb16e3a67599c8e3170f6c72c8712c47d53.1650464054.git.thomas.lendacky@amd.com

During patch review, it was decided the SNP guest driver name should not
be SEV-SNP specific, but should be generic for use with anything SEV.
However, this feedback was missed and the driver name, and many of the
driver functions and structures, are SEV-SNP name specific. Rename the
driver to "sev-guest" (to match the misc device that is created) and
update some of the function and structure names, too.

While in the file, adjust the one pr_err() message to be a dev_err()
message so that the message, if issued, uses the driver name.

Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lore.kernel.org/r/307710bb5515c9088a19fd0b930268c7300479b2.1650464054.git.thomas.lendacky@amd.com

The function enc_payload() is wrongly declared bool but returns an
integer value. Correct it.

  [ bp: Massage commit message. ]

Fixes: fce96cf04430 ("virt: Add SEV-SNP guest driver")
Signed-off-by: Haowen Bai <baihaowen@meizu.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lore.kernel.org/r/1649930657-10837-1-git-send-email-baihaowen@meizu.com

The new efi_secret module exposes the confidential computing (coco)
EFI secret area via securityfs interface.

When the module is loaded (and securityfs is mounted, typically under
/sys/kernel/security), a "secrets/coco" directory is created in
securityfs.  In it, a file is created for each secret entry.  The name
of each such file is the GUID of the secret entry, and its content is
the secret data.

This allows applications running in a confidential computing setting to
read secrets provided by the guest owner via a secure secret injection
mechanism (such as AMD SEV's LAUNCH_SECRET command).

Removing (unlinking) files in the "secrets/coco" directory will zero out
the secret in memory, and remove the filesystem entry.  If the module is
removed and loaded again, that secret will not appear in the filesystem.

Signed-off-by: Dov Murik <dovmurik@linux.ibm.com>
Reviewed-by: Gerd Hoffmann <kraxel@redhat.com>
Link: https://lore.kernel.org/r/20220412212127.154182-3-dovmurik@linux.ibm.com
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>

If alloc_pages() fails, it returns a NULL pointer. Replace the wrong
IS_ERR() check with the proper NULL pointer check.

Fixes: fce96cf04430 ("virt: Add SEV-SNP guest driver")
Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: Yang Yingliang <yangyingliang@huawei.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Brijesh Singh <brijesh.singh@amd.com>
Link: https://lore.kernel.org/r/20220411111213.1477853-1-yangyingliang@huawei.com

Version 2 of GHCB specification defines Non-Automatic-Exit (NAE) to get
extended guest report which is similar to the SNP_GET_REPORT ioctl. The
main difference is related to the additional data that will be returned.

That additional data returned is a certificate blob that can be used by
the SNP guest user. The certificate blob layout is defined in the GHCB
specification. The driver simply treats the blob as a opaque data and
copies it to userspace.

  [ bp: Massage commit message, cast 1st arg of access_ok() ]

Signed-off-by: Brijesh Singh <brijesh.singh@amd.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lore.kernel.org/r/20220307213356.2797205-46-brijesh.singh@amd.com

The SNP_GET_DERIVED_KEY ioctl interface can be used by the SNP guest to
ask the firmware to provide a key derived from a root key. The derived
key may be used by the guest for any purposes it chooses, such as a
sealing key or communicating with the external entities.

See SEV-SNP firmware spec for more information.

  [ bp: No need to memset "req" - it will get overwritten. ]

Signed-off-by: Brijesh Singh <brijesh.singh@amd.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Liam Merwick <liam.merwick@oracle.com>
Link: https://lore.kernel.org/r/20220307213356.2797205-45-brijesh.singh@amd.com