KVM: arm64: Expose self-hosted debug regs as RAZ/WI for protected guests

Debug and trace are not currently supported for protected guests, so
trap accesses to the related registers and emulate them as RAZ/WI for
now. Although this isn't strictly compatible with the architecture, it's
sufficient for Linux guests and means that debug support can be added
later on.

Tested-by: Mostafa Saleh <smostafa@google.com>
Signed-off-by: Fuad Tabba <tabba@google.com>
Signed-off-by: Will Deacon <will@kernel.org>
Link: https://patch.msgid.link/20260330144841.26181-7-will@kernel.org
Signed-off-by: Marc Zyngier <maz@kernel.org>

diff --git a/arch/arm64/kvm/hyp/nvhe/sys_regs.c b/arch/arm64/kvm/hyp/nvhe/sys_regs.c
index 06d28621722eee561df31bc55ca1262a14a4b42a..0a84140afa280b05bfcbfc06277e2c29c1a3e736 100644 (file)
--- a/arch/arm64/kvm/hyp/nvhe/sys_regs.c
+++ b/arch/arm64/kvm/hyp/nvhe/sys_regs.c
@@ -392,6 +392,14 @@ static const struct sys_reg_desc pvm_sys_reg_descs[] = {
        /* Cache maintenance by set/way operations are restricted. */
 
        /* Debug and Trace Registers are restricted. */
+       RAZ_WI(SYS_DBGBVRn_EL1(0)),
+       RAZ_WI(SYS_DBGBCRn_EL1(0)),
+       RAZ_WI(SYS_DBGWVRn_EL1(0)),
+       RAZ_WI(SYS_DBGWCRn_EL1(0)),
+       RAZ_WI(SYS_MDSCR_EL1),
+       RAZ_WI(SYS_OSLAR_EL1),
+       RAZ_WI(SYS_OSLSR_EL1),
+       RAZ_WI(SYS_OSDLR_EL1),
 
        /* Group 1 ID registers */
        HOST_HANDLED(SYS_REVIDR_EL1),