Re: [PATCH 2/4] KVM: PPC: Book3S HV: Fix radix guest SLB side channel

2021-02-09 Thread Nicholas Piggin
Excerpts from Paul Mackerras's message of February 10, 2021 11:28 am: > On Mon, Jan 18, 2021 at 04:28:07PM +1000, Nicholas Piggin wrote: >> The slbmte instruction is legal in radix mode, including radix guest >> mode. This means radix guests can load the SLB with arbitrary data. >> >> KVM host doe

Re: [PATCH 2/4] KVM: PPC: Book3S HV: Fix radix guest SLB side channel

2021-02-09 Thread Paul Mackerras
On Mon, Jan 18, 2021 at 04:28:07PM +1000, Nicholas Piggin wrote: > The slbmte instruction is legal in radix mode, including radix guest > mode. This means radix guests can load the SLB with arbitrary data. > > KVM host does not clear the SLB when exiting a guest if it was a > radix guest, which wo

Re: [PATCH 2/4] KVM: PPC: Book3S HV: Fix radix guest SLB side channel

2021-01-18 Thread Fabiano Rosas
Nicholas Piggin writes: > The slbmte instruction is legal in radix mode, including radix guest > mode. This means radix guests can load the SLB with arbitrary data. > > KVM host does not clear the SLB when exiting a guest if it was a > radix guest, which would allow a rogue radix guest to use the

[PATCH 2/4] KVM: PPC: Book3S HV: Fix radix guest SLB side channel

2021-01-17 Thread Nicholas Piggin
The slbmte instruction is legal in radix mode, including radix guest mode. This means radix guests can load the SLB with arbitrary data. KVM host does not clear the SLB when exiting a guest if it was a radix guest, which would allow a rogue radix guest to use the SLB as a side channel to communica