14 Jan
2019
14 Jan
'19
3:56 p.m.
On Tue, Jan 08, 2019 at 02:07:19PM +0000, Julien Thierry wrote:
When using VHE, the host needs to clear HCR_EL2.TGE bit in order to interract with guest TLBs, switching from EL2&0 translation regime to EL1&0.
However, some non-maskable asynchronous event could happen while TGE is cleared like SDEI. Because of this address translation operations relying on EL2&0 translation regime could fail (tlb invalidation, userspace access, ...).
Why would an NMI context need to access user space? (just curious what breaks exactly without this patch; otherwise it looks fine)
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Catalin