Subject: [PATCH v3 05/36] KVM: arm64: Expose self-hosted debug regs as RAZ/WI for protected guests

From: Will Deacon <[email-masked]>
Date: Thu, 5 Mar 2026 14:43:18 +0000

From: Fuad Tabba <[email-masked]>

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.

Signed-off-by: Fuad Tabba <[email-masked]>
Signed-off-by: Will Deacon <[email-masked]>
---
 arch/arm64/kvm/hyp/nvhe/sys_regs.c | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/arch/arm64/kvm/hyp/nvhe/sys_regs.c b/arch/arm64/kvm/hyp/nvhe/sys_regs.c
index 06d28621722e..0a84140afa28 100644
--- 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),
-- 
2.53.0.473.g4a7958ca14-goog