Re: [PATCH] KVM: arm64: Fix AArch32 DBGBXVR<n> handling
From: Oliver Upton
Date: Sat Sep 19 2026 - 14:12:05 EST
On Mon, 10 Aug 2026 02:56:16 +0200, Karl Mehltretter wrote:
> 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.
>
> [...]
Thanks for pinging, this slipped between the cracks.
Applied to fixes, thanks!
[1/1] KVM: arm64: Fix AArch32 DBGBXVR<n> handling
https://git.kernel.org/kvmarm/kvmarm/c/239763bda716
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Best,
Oliver