diff mbox series

[v10,07/12] KVM: arm64: Allow userspace to change ID_AA64MMFR{0-2}_EL1

Message ID 20230920183310.1163034-8-oliver.upton@linux.dev (mailing list archive)
State New, archived
Headers show
Series KVM: arm64: Enable 'writable' ID registers | expand

Commit Message

Oliver Upton Sept. 20, 2023, 6:33 p.m. UTC 
From: Jing Zhang <jingzhangos@google.com>

Allow userspace to modify the guest-visible values of these ID
registers. Prevent changes to any of the virtualization features until
KVM picks up support for nested and we have a handle on managing NV
features.

Signed-off-by: Jing Zhang <jingzhangos@google.com>
[oliver: prevent changes to EL2 features for now]
Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
---
 arch/arm64/kvm/sys_regs.c | 20 +++++++++++++++++---
 1 file changed, 17 insertions(+), 3 deletions(-)
diff mbox series

Patch

diff --git a/arch/arm64/kvm/sys_regs.c b/arch/arm64/kvm/sys_regs.c
index 71664bec2808..5758cff479d3 100644
--- a/arch/arm64/kvm/sys_regs.c
+++ b/arch/arm64/kvm/sys_regs.c
@@ -2103,9 +2103,23 @@  static const struct sys_reg_desc sys_reg_descs[] = {
 	ID_UNALLOCATED(6,7),
 
 	/* CRm=7 */
-	ID_SANITISED(ID_AA64MMFR0_EL1),
-	ID_SANITISED(ID_AA64MMFR1_EL1),
-	ID_SANITISED(ID_AA64MMFR2_EL1),
+	ID_WRITABLE(ID_AA64MMFR0_EL1, ~(ID_AA64MMFR0_EL1_RES0 |
+					ID_AA64MMFR0_EL1_TGRAN4_2 |
+					ID_AA64MMFR0_EL1_TGRAN64_2 |
+					ID_AA64MMFR0_EL1_TGRAN16_2)),
+	ID_WRITABLE(ID_AA64MMFR1_EL1, ~(ID_AA64MMFR1_EL1_RES0 |
+					ID_AA64MMFR1_EL1_HCX |
+					ID_AA64MMFR1_EL1_XNX |
+					ID_AA64MMFR1_EL1_TWED |
+					ID_AA64MMFR1_EL1_XNX |
+					ID_AA64MMFR1_EL1_VH |
+					ID_AA64MMFR1_EL1_VMIDBits)),
+	ID_WRITABLE(ID_AA64MMFR2_EL1, ~(ID_AA64MMFR2_EL1_RES0 |
+					ID_AA64MMFR2_EL1_EVT |
+					ID_AA64MMFR2_EL1_FWB |
+					ID_AA64MMFR2_EL1_IDS |
+					ID_AA64MMFR2_EL1_NV |
+					ID_AA64MMFR2_EL1_CCIDX)),
 	ID_SANITISED(ID_AA64MMFR3_EL1),
 	ID_UNALLOCATED(7,4),
 	ID_UNALLOCATED(7,5),