[RFC PATCH 11/16] hw/arm/smmuv3: Read VMID from STE

[Mostafa Saleh]

According to SMMUv3 user manual "5.2 Stream Table Entry": All fields
with an S2 prefix (with the exception of S2VMID) are IGNORED when
stage-2 bypasses translation (Config[1] == 0).

Which means that VMID can be used(for TLB tagging) even if stage-2 is
bypassed, so we parse it unconditionally when S2P exists. Otherwise
it is set to -1.(only S1P)

Advertise 16-bit VMID is supported.

Signed-off-by: Mostafa Saleh <smostafa@google.com>
---
 hw/arm/smmuv3.c | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/hw/arm/smmuv3.c b/hw/arm/smmuv3.c
index 769c735697..35a0149bbf 100644
--- a/hw/arm/smmuv3.c
+++ b/hw/arm/smmuv3.c
@@ -260,6 +260,7 @@ static void smmuv3_init_regs(SMMUv3State *s)
     s->idr[0] = FIELD_DP32(s->idr[0], IDR0, TTF, 2); /* AArch64 PTW only */
     s->idr[0] = FIELD_DP32(s->idr[0], IDR0, COHACC, 1); /* IO coherent */
     s->idr[0] = FIELD_DP32(s->idr[0], IDR0, ASID16, 1); /* 16-bit ASID */
+    s->idr[0] = FIELD_DP32(s->idr[0], IDR0, VMID16, 1); /* 16-bit VMID */
     s->idr[0] = FIELD_DP32(s->idr[0], IDR0, TTENDIAN, 2); /* little endian */
     s->idr[0] = FIELD_DP32(s->idr[0], IDR0, STALL_MODEL, 1); /* No stall */
     /* terminated transaction will always be aborted/error returned */
@@ -388,6 +389,14 @@ static int decode_ste(SMMUv3State *s, SMMUTransCfg *cfg,
         return 0;
     }
 
+    if (STAGE2_SUPPORTED(s->features)) {
+        /* VMID is considered even if s2 is disabled. */
+        cfg->s2cfg.vmid = STE_S2VMID(ste);
+    } else {
+        /* Default to -1 */
+        cfg->s2cfg.vmid = -1;
+    }
+
     if (STAGE2_SUPPORTED(s->features) && STE_CFG_S2_ENABLED(config)) {
         cfg->stage = 2;
 
-- 
2.39.1.519.gcb327c4b5f-goog