[PATCH v2] KVM: arm64: Advertise MMFR0 TGRAN for pVMs

[Vincent Donnefort]

protected VM ID register emulation leaves unlisted fields at 0. This
creates two issues for TGRAN:

  * TGRAN16: 0 means non-implemented. It prevents 16KB protected VMs
    from booting even when the hardware supports it.

  * TGRAN4|TGRAN64: 0 means implemented. This may falsely advertise the
    feature even when the hardware does not support it.

Advertise all the TGRAN fields in pvmid_aa64mmfr0 so that the hardware
support is properly propagated.

Fixes: 6c30bfb18d0b ("KVM: arm64: Add handlers for protected VM System Registers")
Tested-by: Fuad Tabba <tabba at google.com>
Reviewed-by: Fuad Tabba <tabba at google.com>
Signed-off-by: Vincent Donnefort <vdonnefort at google.com>
---
 arch/arm64/kvm/hyp/nvhe/sys_regs.c | 3 +++
 1 file changed, 3 insertions(+)

Changelog:

v2:
   - Collect Fuad's tags
   - Reword commit message (Fuad)

v1 (lore.kernel.org/all/20260913203108.3343404-1-vdonnefort at google.com)

diff --git a/arch/arm64/kvm/hyp/nvhe/sys_regs.c b/arch/arm64/kvm/hyp/nvhe/sys_regs.c
index 8758c6801776..ec469d96516a 100644
--- a/arch/arm64/kvm/hyp/nvhe/sys_regs.c
+++ b/arch/arm64/kvm/hyp/nvhe/sys_regs.c
@@ -121,6 +121,9 @@ static const struct pvm_ftr_bits pvmid_aa64mmfr0[] = {
 	MAX_FEAT(ID_AA64MMFR0_EL1, SNSMEM, IMP),
 	MAX_FEAT(ID_AA64MMFR0_EL1, BIGENDEL0, IMP),
 	MAX_FEAT(ID_AA64MMFR0_EL1, EXS, IMP),
+	MAX_FEAT(ID_AA64MMFR0_EL1, TGRAN4, IMP),
+	MAX_FEAT(ID_AA64MMFR0_EL1, TGRAN16, IMP),
+	MAX_FEAT(ID_AA64MMFR0_EL1, TGRAN64, IMP),
 	FEAT_END
 };
 

base-commit: fd73f4a6659897191fa0d40695fe370925dd3780
-- 
2.55.0.1032.g73a4cd73de-goog