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Re: [Qemu-devel] [PATCH v2 3/3] target-arm: get_phys_addr_lpae: more xn
From: |
Peter Maydell |
Subject: |
Re: [Qemu-devel] [PATCH v2 3/3] target-arm: get_phys_addr_lpae: more xn control |
Date: |
Wed, 11 Mar 2015 18:36:51 +0000 |
On 11 March 2015 at 18:30, Andrew Jones <address@hidden> wrote:
> My interpretation of SCTLR_EL1.WXN was just wrong. There is
> talks about "EL1&0"
That's just the name of the translation regime (ie
there's a shared set of page tables that handle
translation for both EL1 and EL0).
> and I assumed it meant that when WXN is
> on, then both EL1 and EL0 should lose executability.
No; and you can see an example of this in the table:
UXN=0, PXN=0, AP[2:1] = 00, WXN=0 is RWX for EL1 and
X for EL0. Setting WXN changes the EL1 rights to just
RW (because the page is writable there) but leaves the
EL0 rights as X (because there the page is not writable).
> However
> it can certainly be interpreted as applying to them both, but
> based on their respective access permissions, which is how
> I guess I should have interpreted it.
Yes, this is the correct interpretation.
-- PMM
- [Qemu-devel] [PATCH v2 1/3] target-arm: convert check_ap to ap_to_rw_prot, (continued)
- [Qemu-devel] [PATCH v2 1/3] target-arm: convert check_ap to ap_to_rw_prot, Andrew Jones, 2015/03/10
- [Qemu-devel] [PATCH v2 2/3] target-arm: fix get_phys_addr_v6/SCTLR_AFE access check, Andrew Jones, 2015/03/10
- [Qemu-devel] [PATCH v2 3/3] target-arm: get_phys_addr_lpae: more xn control, Andrew Jones, 2015/03/10
- Re: [Qemu-devel] [PATCH v2 3/3] target-arm: get_phys_addr_lpae: more xn control, Peter Maydell, 2015/03/11
- Re: [Qemu-devel] [PATCH v2 3/3] target-arm: get_phys_addr_lpae: more xn control, Andrew Jones, 2015/03/11
- Re: [Qemu-devel] [PATCH v2 3/3] target-arm: get_phys_addr_lpae: more xn control, Peter Maydell, 2015/03/11
- Re: [Qemu-devel] [PATCH v2 3/3] target-arm: get_phys_addr_lpae: more xn control, Andrew Jones, 2015/03/11
- Re: [Qemu-devel] [PATCH v2 3/3] target-arm: get_phys_addr_lpae: more xn control, Peter Maydell, 2015/03/11
- Re: [Qemu-devel] [PATCH v2 3/3] target-arm: get_phys_addr_lpae: more xn control, Andrew Jones, 2015/03/11
- Re: [Qemu-devel] [PATCH v2 3/3] target-arm: get_phys_addr_lpae: more xn control,
Peter Maydell <=