mirrors/qemu
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

target/arm: Handle FEAT_NV page table attribute changes

Browse Source 
FEAT_NV requires that when HCR_EL2.{NV,NV1} == {1,1} the handling
of some of the page table attribute bits changes for the EL1&0
translation regime:

 * for block and page descriptors:
  - bit [54] holds PXN, not UXN
  - bit [53] is RES0, and the effective value of UXN is 0
  - bit [6], AP[1], is treated as 0
 * for table descriptors, when hierarchical permissions are enabled:
  - bit [60] holds PXNTable, not UXNTable
  - bit [59] is RES0
  - bit [61], APTable[0] is treated as 0

Implement these changes to the page table attribute handling.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Tested-by: Miguel Luis <miguel.luis@oracle.com>
This commit is contained in:
Peter Maydell 2024-01-09 14:43:51 +00:00
parent 2e9b1e50bd
commit dea9104a4f
1 changed files with 21 additions and 0 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

21
target/arm/ptw.c
View File

@ -1581,6 +1581,12 @@ static bool lpae_block_desc_valid(ARMCPU *cpu, bool ds,
}
}
static bool nv_nv1_enabled(CPUARMState *env, S1Translate *ptw)
{
uint64_t hcr = arm_hcr_el2_eff_secstate(env, ptw->in_space);
return (hcr & (HCR_NV | HCR_NV1)) == (HCR_NV | HCR_NV1);
}
/**
* get_phys_addr_lpae: perform one stage of page table walk, LPAE format
*
@ -1989,6 +1995,21 @@ static bool get_phys_addr_lpae(CPUARMState *env, S1Translate *ptw,
xn = extract64(attrs, 54, 1);
pxn = extract64(attrs, 53, 1);
if (el == 1 && nv_nv1_enabled(env, ptw)) {
/*
* With FEAT_NV, when HCR_EL2.{NV,NV1} == {1,1}, the block/page
* descriptor bit 54 holds PXN, 53 is RES0, and the effective value
* of UXN is 0. Similarly for bits 59 and 60 in table descriptors
* (which we have already folded into bits 53 and 54 of attrs).
* AP[1] (descriptor bit 6, our ap bit 0) is treated as 0.
* Similarly, APTable[0] from the table descriptor is treated as 0;
* we already folded this into AP[1] and squashing that to 0 does
* the right thing.
*/
pxn = xn;
xn = 0;
ap &= ~1;
}
/*
* Note that we modified ptw->in_space earlier for NSTable, but
* result->f.attrs retains a copy of the original security space.