Add Svukte extension support #2121
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aswaterman
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aswaterman
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@ingallsj can I delegate to you to review this, particularly the various cases in check_svukte_qualified?
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Hi @aswaterman
Modification by your suggestion has been done.
Many thanks for review
binno
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binno
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Hi @aswaterman
Modification by your suggestion has been done.
Please help to review it again
This adds support for the Svukte extension, which adds support for address-independent latency of user-mode faults to supervisor addresses.
| if (proc->extension_enabled('S') && get_field(state->senvcfg->read(), SENVCFG_UKTE)) { | ||
| if (forced_virt && state->prv == PRV_U) { | ||
| bool hstatus_hukte = proc->extension_enabled('H') && (get_field(state->hstatus->read(), HSTATUS_HUKTE) == 1); | ||
| return !hstatus_hukte; |
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I feel like there should be an address check before this return statement.
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I think there's both an actual bug and a conceptual bug here. Per the spec, "Svukte-qualified" is a property of an access type, not an address. Either this function should not accept an address arg, or it should be renamed. That might be why this bug cropped up. I'll make a fix.
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I think the address check is in line 587
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But if you hit the return statement, you never reach like 587, so the address never gets checked for HLV/HSV in U-mode.
I think my PR #2171 fixes this case.
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| assert(proc->get_xlen() == 64); | ||
| if ((addr >> 63) & 1) { | ||
| return (state->v || forced_virt) && ((state->vsatp->read() & SATP64_MODE) == 0); |
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Am I understanding this return statement correctly, that we pass the Svukte check if in VU mode and vsatp.MODE == Bare? Where do we check satp for when in HU mode?
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This adds support for the Svukte extension, which adds support for address-independent latency of user-mode faults to supervisor addresses.