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From: Sasha Levin <sashal@kernel.org>
To: vdonnefort@google.com, fuad.tabba@linux.dev, tabba@google.com,
	maz@kernel.org
Cc: stable@vger.kernel.org
Subject: FAILED: patch "[PATCH] KVM: arm64: Fix MMFR0 TGRAN advertisement for pVMs" failed to apply to 6.6-stable tree
Date: Sat,  7 Nov 2026 05:31:04 -0500	[thread overview]
Message-ID: <20261107053104-failed-6.6-6c29285e78b5@kernel.org> (raw)

The patch below does not apply to the 6.6-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable@vger.kernel.org>.

To reproduce the conflict and resubmit, you may use the following commands:

git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-6.6.y
git checkout FETCH_HEAD
git cherry-pick -x 6c29285e78b5e4811145ebda382ac0ba732ce56a
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable@vger.kernel.org>' --in-reply-to '20261107053104-failed-6.6-6c29285e78b5@kernel.org' --subject-prefix 'PATCH 6.6.y' 'HEAD^..'

Thanks,
Sasha

------------------ original commit in Linus's tree ------------------

From 6c29285e78b5e4811145ebda382ac0ba732ce56a Mon Sep 17 00:00:00 2001
From: Vincent Donnefort <vdonnefort@google.com>
Date: Mon, 28 Sep 2026 10:54:50 +0100
Subject: [PATCH] KVM: arm64: Fix MMFR0 TGRAN advertisement for pVMs

Protected VM ID register emulation leaves unlisted fields at 0. This
creates two issues for TGRAN:

  * TGRAN16: 0 means non-implemented. It prevents 16KB protected VMs
    from booting even when the hardware supports it.

  * TGRAN4|TGRAN64: 0 means implemented. This may falsely advertise the
    feature even when the hardware does not support it.

Advertise all the TGRAN fields in pvmid_aa64mmfr0 so that the hardware
support is properly propagated.

Cc: stable@vger.kernel.org
Fixes: 6c30bfb18d0b ("KVM: arm64: Add handlers for protected VM System Registers")
Signed-off-by: Vincent Donnefort <vdonnefort@google.com>
Tested-by: Fuad Tabba <fuad.tabba@linux.dev>
Reviewed-by: Fuad Tabba <fuad.tabba@linux.dev>
Tested-by: Fuad Tabba <tabba@google.com>
Reviewed-by: Fuad Tabba <tabba@google.com>
Link: https://patch.msgid.link/20260928095454.3255918-2-vdonnefort@google.com
Signed-off-by: Marc Zyngier <maz@kernel.org>
---
 arch/arm64/kvm/hyp/nvhe/sys_regs.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/arch/arm64/kvm/hyp/nvhe/sys_regs.c b/arch/arm64/kvm/hyp/nvhe/sys_regs.c
index 8758c68017765..ec469d96516a5 100644
--- a/arch/arm64/kvm/hyp/nvhe/sys_regs.c
+++ b/arch/arm64/kvm/hyp/nvhe/sys_regs.c
@@ -121,6 +121,9 @@ static const struct pvm_ftr_bits pvmid_aa64mmfr0[] = {
 	MAX_FEAT(ID_AA64MMFR0_EL1, SNSMEM, IMP),
 	MAX_FEAT(ID_AA64MMFR0_EL1, BIGENDEL0, IMP),
 	MAX_FEAT(ID_AA64MMFR0_EL1, EXS, IMP),
+	MAX_FEAT(ID_AA64MMFR0_EL1, TGRAN4, IMP),
+	MAX_FEAT(ID_AA64MMFR0_EL1, TGRAN16, IMP),
+	MAX_FEAT(ID_AA64MMFR0_EL1, TGRAN64, IMP),
 	FEAT_END
 };
 
-- 
2.53.0





             reply	other threads:[~2026-11-07 10:31 UTC|newest]

Thread overview: 2+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2026-11-07 10:31 Sasha Levin [this message]
2026-11-10 14:33 ` [PATCH 6.6.y] KVM: arm64: Fix MMFR0 TGRAN advertisement for pVMs Sasha Levin

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