From: Joe Komlodi <joe.komlodi@xilinx.com>
To: <qemu-devel@nongnu.org>
Cc: eric.auger@redhat.com, qemu-arm@nongnu.org
Subject: [PATCH 1/1] hw/arm/smmu: Add access flag handling
Date: Fri, 30 Jul 2021 16:17:02 -0700 [thread overview]
Message-ID: <1627687022-366528-2-git-send-email-joe.komlodi@xilinx.com> (raw)
In-Reply-To: <1627687022-366528-1-git-send-email-joe.komlodi@xilinx.com>
The SMMU should access fault if AF == 0 in a TTD, and if AFFD == 0 in the CD.
Per the spec, an access fault has a higher priority over a permission fault.
For instance, a write to a writable clean (temporarily non-writable) page with
AF == 0 && AFFD == 0 will cause an access fault.
If AF == 1 in this situation, then a permission fault would occur.
Access flag handling is more complicated if HTTU is supported and HA != 0 in
the CD, however we currently do not support HTTU.
Signed-off-by: Joe Komlodi <joe.komlodi@xilinx.com>
---
hw/arm/smmu-common.c | 7 +++++++
hw/arm/smmu-internal.h | 8 ++++++++
hw/arm/smmuv3-internal.h | 1 +
hw/arm/smmuv3.c | 1 +
include/hw/arm/smmu-common.h | 1 +
5 files changed, 18 insertions(+)
diff --git a/hw/arm/smmu-common.c b/hw/arm/smmu-common.c
index 0459850..0fcc65c 100644
--- a/hw/arm/smmu-common.c
+++ b/hw/arm/smmu-common.c
@@ -305,6 +305,7 @@ static int smmu_ptw_64(SMMUTransCfg *cfg,
uint64_t pte, gpa;
dma_addr_t pte_addr = baseaddr + offset * sizeof(pte);
uint8_t ap;
+ bool af;
if (get_pte(baseaddr, offset, &pte, info)) {
goto error;
@@ -341,6 +342,12 @@ static int smmu_ptw_64(SMMUTransCfg *cfg,
pte_addr, pte, iova, gpa,
block_size >> 20);
}
+ af = PTE_AF(pte);
+ if (is_access_fault(af, perm)) {
+ info->type = SMMU_PTW_ERR_ACCESS;
+ goto error;
+ }
+
ap = PTE_AP(pte);
if (is_permission_fault(ap, perm)) {
info->type = SMMU_PTW_ERR_PERMISSION;
diff --git a/hw/arm/smmu-internal.h b/hw/arm/smmu-internal.h
index 2d75b31..9d3b22c 100644
--- a/hw/arm/smmu-internal.h
+++ b/hw/arm/smmu-internal.h
@@ -58,6 +58,11 @@
((level == 3) && \
((pte & ARM_LPAE_PTE_TYPE_MASK) == ARM_LPAE_L3_PTE_TYPE_PAGE))
+/* access flag */
+
+#define PTE_AF(pte) \
+ (extract64(pte, 10, 1))
+
/* access permissions */
#define PTE_AP(pte) \
@@ -66,6 +71,9 @@
#define PTE_APTABLE(pte) \
(extract64(pte, 61, 2))
+#define is_access_fault(af, cfg) \
+ (!cfg->affd && !af)
+
/*
* TODO: At the moment all transactions are considered as privileged (EL1)
* as IOMMU translation callback does not pass user/priv attributes.
diff --git a/hw/arm/smmuv3-internal.h b/hw/arm/smmuv3-internal.h
index d1885ae..0ccad1d 100644
--- a/hw/arm/smmuv3-internal.h
+++ b/hw/arm/smmuv3-internal.h
@@ -587,6 +587,7 @@ static inline int pa_range(STE *ste)
#define CD_EPD(x, sel) extract32((x)->word[0], (16 * (sel)) + 14, 1)
#define CD_ENDI(x) extract32((x)->word[0], 15, 1)
#define CD_IPS(x) extract32((x)->word[1], 0 , 3)
+#define CD_AFFD(x) extract32((x)->word[1], 3 , 1)
#define CD_TBI(x) extract32((x)->word[1], 6 , 2)
#define CD_HD(x) extract32((x)->word[1], 10 , 1)
#define CD_HA(x) extract32((x)->word[1], 11 , 1)
diff --git a/hw/arm/smmuv3.c b/hw/arm/smmuv3.c
index 01b60be..df5a194 100644
--- a/hw/arm/smmuv3.c
+++ b/hw/arm/smmuv3.c
@@ -483,6 +483,7 @@ static int decode_cd(SMMUTransCfg *cfg, CD *cd, SMMUEventInfo *event)
cfg->oas = MIN(oas2bits(SMMU_IDR5_OAS), cfg->oas);
cfg->tbi = CD_TBI(cd);
cfg->asid = CD_ASID(cd);
+ cfg->affd = CD_AFFD(cd);
trace_smmuv3_decode_cd(cfg->oas);
diff --git a/include/hw/arm/smmu-common.h b/include/hw/arm/smmu-common.h
index 706be3c..b0e82ad 100644
--- a/include/hw/arm/smmu-common.h
+++ b/include/hw/arm/smmu-common.h
@@ -71,6 +71,7 @@ typedef struct SMMUTransCfg {
bool disabled; /* smmu is disabled */
bool bypassed; /* translation is bypassed */
bool aborted; /* translation is aborted */
+ bool affd; /* Access Flag Fault Disabled */
uint64_t ttb; /* TT base address */
uint8_t oas; /* output address width */
uint8_t tbi; /* Top Byte Ignore */
--
2.7.4
next prev parent reply other threads:[~2021-07-30 23:18 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-07-30 23:17 [PATCH 0/1] hw/arm/smmu: Add access flag handling Joe Komlodi
2021-07-30 23:17 ` Joe Komlodi [this message]
2021-08-04 16:45 ` [PATCH 1/1] " Eric Auger
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