target/arm/ptw: Only fold in NSTable bit effects in Secure state

When we do a translation in Secure state, the NSTable bits in table
descriptors may downgrade us to NonSecure; we update ptw->in_secure
and ptw->in_space accordingly.  We guard that check correctly with a
conditional that means it's only applied for Secure stage 1
translations.  However, later on in get_phys_addr_lpae() we fold the
effects of the NSTable bits into the final descriptor attributes
bits, and there we do it unconditionally regardless of the CPU state.
That means that in Realm state (where in_secure is false) we will set
bit 5 in attrs, and later use it to decide to output to non-secure
space.

We don't in fact need to do this folding in at all any more (since
commit 2f1ff4e7b9f30c): if an NSTable bit was set then we have
already set ptw->in_space to ARMSS_NonSecure, and in that situation
we don't look at attrs bit 5.  The only thing we still need to deal
with is the real NS bit in the final descriptor word, so we can just
drop the code that ORed in the NSTable bit.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20230807141514.19075-9-peter.maydell@linaro.org

diff --git a/target/arm/ptw.c b/target/arm/ptw.c
index 4c60de753dd342ff6877dd0e370b1772bd0059be..6e736bacd77f3aefe1091ad7fecc32a3a97617d5 100644 (file)
--- a/target/arm/ptw.c
+++ b/target/arm/ptw.c
@@ -1886,11 +1886,10 @@ static bool get_phys_addr_lpae(CPUARMState *env, S1Translate *ptw,
      * Extract attributes from the (modified) descriptor, and apply
      * table descriptors. Stage 2 table descriptors do not include
      * any attribute fields. HPD disables all the table attributes
-     * except NSTable.
+     * except NSTable (which we have already handled).
      */
     attrs = new_descriptor & (MAKE_64BIT_MASK(2, 10) | MAKE_64BIT_MASK(50, 14));
     if (!regime_is_stage2(mmu_idx)) {
-        attrs |= !ptw->in_secure << 5; /* NS */
         if (!param.hpd) {
             attrs |= extract64(tableattrs, 0, 2) << 53;     /* XN, PXN */
             /*