[PATCH v5 09/14] target/arm: Don't shift attrs in get_phys_addr_lpae

Richard Henderson posted 14 patches 3 years, 3 months ago
Maintainers: Peter Maydell <peter.maydell@linaro.org>
There is a newer version of this series
[PATCH v5 09/14] target/arm: Don't shift attrs in get_phys_addr_lpae
Posted by Richard Henderson 3 years, 3 months ago
Leave the upper and lower attributes in the place they originate
from in the descriptor.  Shifting them around is confusing, since
one cannot read the bit numbers out of the manual.  Also, new
attributes have been added which would alter the shifts.

Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
---
 target/arm/ptw.c | 31 +++++++++++++++----------------
 1 file changed, 15 insertions(+), 16 deletions(-)

diff --git a/target/arm/ptw.c b/target/arm/ptw.c
index cd16b42c96..6820c2f4bc 100644
--- a/target/arm/ptw.c
+++ b/target/arm/ptw.c
@@ -1069,7 +1069,7 @@ static bool get_phys_addr_lpae(CPUARMState *env, S1Translate *ptw,
     hwaddr descaddr, indexmask, indexmask_grainsize;
     uint32_t tableattrs;
     target_ulong page_size;
-    uint32_t attrs;
+    uint64_t attrs;
     int32_t stride;
     int addrsize, inputsize, outputsize;
     uint64_t tcr = regime_tcr(env, mmu_idx);
@@ -1343,49 +1343,48 @@ static bool get_phys_addr_lpae(CPUARMState *env, S1Translate *ptw,
     descaddr &= ~(hwaddr)(page_size - 1);
     descaddr |= (address & (page_size - 1));
     /* Extract attributes from the descriptor */
-    attrs = extract64(descriptor, 2, 10)
-        | (extract64(descriptor, 52, 12) << 10);
+    attrs = descriptor & (MAKE_64BIT_MASK(2, 10) | MAKE_64BIT_MASK(52, 12));
 
     if (regime_is_stage2(mmu_idx)) {
         /* Stage 2 table descriptors do not include any attribute fields */
         goto skip_attrs;
     }
     /* Merge in attributes from table descriptors */
-    attrs |= nstable << 3; /* NS */
+    attrs |= nstable << 5; /* NS */
     guarded = extract64(descriptor, 50, 1);  /* GP */
     if (param.hpd) {
         /* HPD disables all the table attributes except NSTable.  */
         goto skip_attrs;
     }
-    attrs |= extract32(tableattrs, 0, 2) << 11;     /* XN, PXN */
+    attrs |= extract64(tableattrs, 0, 2) << 53;     /* XN, PXN */
     /*
      * The sense of AP[1] vs APTable[0] is reversed, as APTable[0] == 1
      * means "force PL1 access only", which means forcing AP[1] to 0.
      */
-    attrs &= ~(extract32(tableattrs, 2, 1) << 4);   /* !APT[0] => AP[1] */
-    attrs |= extract32(tableattrs, 3, 1) << 5;      /* APT[1] => AP[2] */
+    attrs &= ~(extract64(tableattrs, 2, 1) << 6);   /* !APT[0] => AP[1] */
+    attrs |= extract32(tableattrs, 3, 1) << 7;      /* APT[1] => AP[2] */
  skip_attrs:
 
     /*
      * Here descaddr is the final physical address, and attributes
      * are all in attrs.
      */
-    if ((attrs & (1 << 8)) == 0) {
+    if ((attrs & (1 << 10)) == 0) {
         /* Access flag */
         fi->type = ARMFault_AccessFlag;
         goto do_fault;
     }
 
-    ap = extract32(attrs, 4, 2);
+    ap = extract32(attrs, 6, 2);
 
     if (regime_is_stage2(mmu_idx)) {
         ns = mmu_idx == ARMMMUIdx_Stage2;
-        xn = extract32(attrs, 11, 2);
+        xn = extract64(attrs, 54, 2);
         result->f.prot = get_S2prot(env, ap, xn, s1_is_el0);
     } else {
-        ns = extract32(attrs, 3, 1);
-        xn = extract32(attrs, 12, 1);
-        pxn = extract32(attrs, 11, 1);
+        ns = extract32(attrs, 5, 1);
+        xn = extract64(attrs, 54, 1);
+        pxn = extract64(attrs, 53, 1);
         result->f.prot = get_S1prot(env, mmu_idx, aarch64, ap, ns, xn, pxn);
     }
 
@@ -1410,10 +1409,10 @@ static bool get_phys_addr_lpae(CPUARMState *env, S1Translate *ptw,
 
     if (regime_is_stage2(mmu_idx)) {
         result->cacheattrs.is_s2_format = true;
-        result->cacheattrs.attrs = extract32(attrs, 0, 4);
+        result->cacheattrs.attrs = extract32(attrs, 2, 4);
     } else {
         /* Index into MAIR registers for cache attributes */
-        uint8_t attrindx = extract32(attrs, 0, 3);
+        uint8_t attrindx = extract32(attrs, 2, 3);
         uint64_t mair = env->cp15.mair_el[regime_el(env, mmu_idx)];
         assert(attrindx <= 7);
         result->cacheattrs.is_s2_format = false;
@@ -1428,7 +1427,7 @@ static bool get_phys_addr_lpae(CPUARMState *env, S1Translate *ptw,
     if (param.ds) {
         result->cacheattrs.shareability = param.sh;
     } else {
-        result->cacheattrs.shareability = extract32(attrs, 6, 2);
+        result->cacheattrs.shareability = extract32(attrs, 8, 2);
     }
 
     result->f.phys_addr = descaddr;
-- 
2.34.1
Re: [PATCH v5 09/14] target/arm: Don't shift attrs in get_phys_addr_lpae
Posted by Philippe Mathieu-Daudé 3 years, 3 months ago
On 21/10/22 00:35, Richard Henderson wrote:
> Leave the upper and lower attributes in the place they originate
> from in the descriptor.  Shifting them around is confusing, since
> one cannot read the bit numbers out of the manual.  Also, new
> attributes have been added which would alter the shifts.
> 
> Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
> Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
> ---
>   target/arm/ptw.c | 31 +++++++++++++++----------------
>   1 file changed, 15 insertions(+), 16 deletions(-)

>       if (regime_is_stage2(mmu_idx)) {
>           ns = mmu_idx == ARMMMUIdx_Stage2;
> -        xn = extract32(attrs, 11, 2);
> +        xn = extract64(attrs, 54, 2);

54 -> 53?
Re: [PATCH v5 09/14] target/arm: Don't shift attrs in get_phys_addr_lpae
Posted by Peter Maydell 3 years, 3 months ago
On Fri, 21 Oct 2022 at 10:27, Philippe Mathieu-Daudé <philmd@linaro.org> wrote:
>
> On 21/10/22 00:35, Richard Henderson wrote:
> > Leave the upper and lower attributes in the place they originate
> > from in the descriptor.  Shifting them around is confusing, since
> > one cannot read the bit numbers out of the manual.  Also, new
> > attributes have been added which would alter the shifts.
> >
> > Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
> > Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
> > ---
> >   target/arm/ptw.c | 31 +++++++++++++++----------------
> >   1 file changed, 15 insertions(+), 16 deletions(-)
>
> >       if (regime_is_stage2(mmu_idx)) {
> >           ns = mmu_idx == ARMMMUIdx_Stage2;
> > -        xn = extract32(attrs, 11, 2);
> > +        xn = extract64(attrs, 54, 2);
>
> 54 -> 53?

Yes. I spotted that in review of v3 but I guess we lost the fix
along the way somewhere.

-- PMM