KVM: arm64: Fix AArch32 DBGBXVR<n> handling

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The consolidation of the breakpoint and watchpoint register accessors
switched DBGBXVR<n> from trap_bvr() to trap_dbg_wb_reg(). The latter
selects backing storage with demux_wb_reg(), which only handles Op2 values
4 through 7. Since DBGBXVR<n> uses Op2 1, an AArch32 guest access hits
KVM_BUG_ON() and marks the VM dead.

DBGBXVR<n> aliases DBGBVR<n>_EL1[63:32], and its AA32(HI) descriptor
already selects the upper half. Map Op2 1 to dbg_bvr[] alongside Op2 4,
restoring the pre-regression behavior.

Fixes: 3ce9f3357e ("KVM: arm64: Fold DBGxVR/DBGxCR accessors into common set")
Cc: stable@vger.kernel.org
Assisted-by: Claude:claude-opus-5
Signed-off-by: Karl Mehltretter <kmehltretter@gmail.com>
Reviewed-by: Marc Zyngier <maz@kernel.org>
Link: https://patch.msgid.link/20260810005616.13227-1-kmehltretter@gmail.com
Signed-off-by: Oliver Upton <oupton@kernel.org>

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Karl Mehltretter 2026-08-10 02:56:16 +02:00 • committed by Oliver Upton

parent 089e4f3c48

commit 6b1bca1b1a

1 changed files with 1 additions and 0 deletions

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arch/arm64/kvm/sys_regs.c

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