commit | 52e7aa3245d7cc74886630ab2c85cd3c5afe21dd | [log] [tgz] |
---|---|---|
author | Marc Zyngier <maz@kernel.org> | Tue Oct 11 17:54:00 2022 +0100 |
committer | Vincent Donnefort <vdonnefort@google.com> | Wed Nov 09 15:27:20 2022 +0000 |
tree | 24898d329861dcb0a5015c6b005c6a88ed2cb2ec | |
parent | bcb19fa29658768dd596182be44acaafab593b1e [diff] |
FROMLIST: KVM: arm64: pkvm: Fixup boot mode to reflect that the kernel resumes from EL1 The kernel has an awfully complicated boot sequence in order to cope with the various EL2 configurations, including those that "enhanced" the architecture. We go from EL2 to EL1, then back to EL2, staying at EL2 if VHE capable and otherwise go back to EL1. Here's a paracetamol tablet for you. The cpu_resume path follows the same logic, because coming up with two versions of a square wheel is hard. However, things aren't this straightforward with pKVM, as the host resume path is always proxied by the hypervisor, which means that the kernel is always entered at EL1. Which contradicts what the __boot_cpu_mode[] array contains (it obviously says EL2). This thus triggers a HVC call from EL1 to EL2 in a vain attempt to upgrade from EL1 to EL2 VHE, which we are, funnily enough, reluctant to grant to the host kernel. This is also completely unexpected, and puzzles your average EL2 hacker. Address it by fixing up the boot mode at the point the host gets deprivileged. is_hyp_mode_available() and co already have a static branch to deal with this, making it pretty safe. Cc: <stable@vger.kernel.org> # 5.15+ Reported-by: Vincent Donnefort <vdonnefort@google.com> Signed-off-by: Marc Zyngier <maz@kernel.org> Tested-by: Vincent Donnefort <vdonnefort@google.com> Bug: 258157858 Link: https://lore.kernel.org/all/20221108100138.3887862-1-vdonnefort@google.com/ Change-Id: I4a2269402ececa0ec47cab88343c3c623b4b2e3d
BEST: Make all of your changes to upstream Linux. If appropriate, backport to the stable releases. These patches will be merged automatically in the corresponding common kernels. If the patch is already in upstream Linux, post a backport of the patch that conforms to the patch requirements below.
EXPORT_SYMBOL_GPL()
require an in-tree modular driver that uses the symbol -- so include the new driver or changes to an existing driver in the same patchset as the export.LESS GOOD: Develop your patches out-of-tree (from an upstream Linux point-of-view). Unless these are fixing an Android-specific bug, these are very unlikely to be accepted unless they have been coordinated with kernel-team@android.com. If you want to proceed, post a patch that conforms to the patch requirements below.
script/checkpatch.pl
UPSTREAM:
, BACKPORT:
, FROMGIT:
, FROMLIST:
, or ANDROID:
.Change-Id:
tag (see https://gerrit-review.googlesource.com/Documentation/user-changeid.html)Bug:
tag.Signed-off-by:
tag by the author and the submitterAdditional requirements are listed below based on patch type
UPSTREAM:
, BACKPORT:
UPSTREAM:
.(cherry picked from commit ...)
lineimportant patch from upstream This is the detailed description of the important patch Signed-off-by: Fred Jones <fred.jones@foo.org>
- then Joe Smith would upload the patch for the common kernel as
UPSTREAM: important patch from upstream This is the detailed description of the important patch Signed-off-by: Fred Jones <fred.jones@foo.org> Bug: 135791357 Change-Id: I4caaaa566ea080fa148c5e768bb1a0b6f7201c01 (cherry picked from commit c31e73121f4c1ec41143423ac6ce3ce6dafdcec1) Signed-off-by: Joe Smith <joe.smith@foo.org>
BACKPORT:
instead of UPSTREAM:
.UPSTREAM:
(cherry picked from commit ...)
lineBACKPORT: important patch from upstream This is the detailed description of the important patch Signed-off-by: Fred Jones <fred.jones@foo.org> Bug: 135791357 Change-Id: I4caaaa566ea080fa148c5e768bb1a0b6f7201c01 (cherry picked from commit c31e73121f4c1ec41143423ac6ce3ce6dafdcec1) [joe: Resolved minor conflict in drivers/foo/bar.c ] Signed-off-by: Joe Smith <joe.smith@foo.org>
FROMGIT:
, FROMLIST:
,FROMGIT:
(cherry picked from commit <sha1> <repo> <branch>)
. This must be a stable maintainer branch (not rebased, so don't use linux-next
for example).BACKPORT: FROMGIT:
important patch from upstream This is the detailed description of the important patch Signed-off-by: Fred Jones <fred.jones@foo.org>
- then Joe Smith would upload the patch for the common kernel as
FROMGIT: important patch from upstream This is the detailed description of the important patch Signed-off-by: Fred Jones <fred.jones@foo.org> Bug: 135791357 (cherry picked from commit 878a2fd9de10b03d11d2f622250285c7e63deace https://git.kernel.org/pub/scm/linux/kernel/git/foo/bar.git test-branch) Change-Id: I4caaaa566ea080fa148c5e768bb1a0b6f7201c01 Signed-off-by: Joe Smith <joe.smith@foo.org>
FROMLIST:
Link:
tag with a link to the submittal on lore.kernel.orgBug:
tag with the Android bug (required for patches not accepted into a maintainer tree)BACKPORT: FROMLIST:
FROMLIST: important patch from upstream This is the detailed description of the important patch Signed-off-by: Fred Jones <fred.jones@foo.org> Bug: 135791357 Link: https://lore.kernel.org/lkml/20190619171517.GA17557@someone.com/ Change-Id: I4caaaa566ea080fa148c5e768bb1a0b6f7201c01 Signed-off-by: Joe Smith <joe.smith@foo.org>
ANDROID:
ANDROID:
Fixes:
tag that cites the patch with the bugANDROID: fix android-specific bug in foobar.c This is the detailed description of the important fix Fixes: 1234abcd2468 ("foobar: add cool feature") Change-Id: I4caaaa566ea080fa148c5e768bb1a0b6f7201c01 Signed-off-by: Joe Smith <joe.smith@foo.org>
ANDROID:
Bug:
tag with the Android bug (required for android-specific features)