Change the way stage 2 page table is managed #193
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zpzigi754
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| new_s2tte |= bits_in_reg(S2TTE::NS, 1) | ||
| | bits_in_reg(S2TTE::XN, 1) | ||
| | bits_in_reg(S2TTE::AF, 1) | ||
| | bits_in_reg(S2TTE::DESC_TYPE, desc_type::L3_PAGE); |
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What's the reason of removing bits_in_reg(S2TTE::MEMATTR, pte::attribute::NORMAL_FWB) and bits_in_reg(S2TTE::SH, pte::shareable::INNER)?
Without this, doesn't it make the access non-cacheable and non-sharable?
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I found that host_s2tte, which is one of prameters for RMI_RTT_MAP_UNPROTECTED, already includes the properties. So it will eventually inculde chachability(FWB), sharability(inner ), access permission(RW)
https://github.com/Samsung/islet-asset/blob/604bc2c405be75be6645ddf1dcfeeca8bbd86b9f/arch/arm64/kvm/rme.c#L646
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Thank you for the investigation!
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This commit is the implementation of the previous discussion (https://github.com//discussions/180). The stage 2 page table will be constructed in the location where the Host has intended with the APIs at the right timing.
Realm-linux's stage 2 page table walking starts from level 2 instead of level 0. It also consists of 8 concatenated tables. This commit handles the table's difference with `realm-linux` feature. A refactoring work would be needed to remove this feature in the future.
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This PR is the implementation of the previous discussion. The stage 2 page table will be constructed in the location and timing where the Host has intended with the APIs.
Page table difference handling
The host can determine the type of the stage 2 table. For example, realm-linux's stage 2 page table walking starts from level 2 instead of level 0 while using 8 concatenated tables. This PR handles the table's difference with
realm-linuxfeature and configurableVTCR(Virtualization Translation Control Register). A refactoring work would be needed to remove the feature in the future.Result summary
Regarding
tf-a-tests,This PR will pass all rmi-related tests (We don't conduct rsi checks yet).
Regarding
ACS tests, this willpass 2 additional checks in
rtt_read_entrypass 13 additional checks in
rtt_init_ripaspass 16 additional checks in
rtt_createpass 4 additional checks in
cmd_data_createmiss 1 additional checks in
realm_activatepass all checks in
mm_rtt_level_start