Re: [PATCH] x86/AMD: expose SYSCFG, TOM, and TOM2 to Dom0

2021-05-27 Thread Roger Pau Monné
On Thu, May 27, 2021 at 04:57:04PM +0200, Jan Beulich wrote: > On 27.05.2021 15:23, Roger Pau Monné wrote: > > On Thu, May 27, 2021 at 12:41:51PM +0200, Jan Beulich wrote: > >> On 27.05.2021 10:33, Roger Pau Monné wrote: > >>> On Wed, May 26, 2021 at 02:59:00PM +0200, Jan Beulich wrote: > Suff

Re: [PATCH] x86/AMD: expose SYSCFG, TOM, and TOM2 to Dom0

2021-05-27 Thread Jan Beulich
On 27.05.2021 15:23, Roger Pau Monné wrote: > On Thu, May 27, 2021 at 12:41:51PM +0200, Jan Beulich wrote: >> On 27.05.2021 10:33, Roger Pau Monné wrote: >>> On Wed, May 26, 2021 at 02:59:00PM +0200, Jan Beulich wrote: Sufficiently old Linux (3.12-ish) accesses these MSRs in an unguarded

Re: [PATCH] x86/AMD: expose SYSCFG, TOM, and TOM2 to Dom0

2021-05-27 Thread Roger Pau Monné
On Thu, May 27, 2021 at 12:41:51PM +0200, Jan Beulich wrote: > On 27.05.2021 10:33, Roger Pau Monné wrote: > > On Wed, May 26, 2021 at 02:59:00PM +0200, Jan Beulich wrote: > >> Sufficiently old Linux (3.12-ish) accesses these MSRs in an unguarded > >> manner. Furthermore these MSRs, at least on Fam

Re: [PATCH] x86/AMD: expose SYSCFG, TOM, and TOM2 to Dom0

2021-05-27 Thread Jan Beulich
On 27.05.2021 10:33, Roger Pau Monné wrote: > On Wed, May 26, 2021 at 02:59:00PM +0200, Jan Beulich wrote: >> Sufficiently old Linux (3.12-ish) accesses these MSRs in an unguarded >> manner. Furthermore these MSRs, at least on Fam11 and older CPUs, are >> also consulted by modern Linux, and their (

Re: [PATCH] x86/AMD: expose SYSCFG, TOM, and TOM2 to Dom0

2021-05-27 Thread Roger Pau Monné
On Wed, May 26, 2021 at 02:59:00PM +0200, Jan Beulich wrote: > Sufficiently old Linux (3.12-ish) accesses these MSRs in an unguarded > manner. Furthermore these MSRs, at least on Fam11 and older CPUs, are > also consulted by modern Linux, and their (bogus) built-in zapping of > #GP faults from MSR

[PATCH] x86/AMD: expose SYSCFG, TOM, and TOM2 to Dom0

2021-05-26 Thread Jan Beulich
Sufficiently old Linux (3.12-ish) accesses these MSRs in an unguarded manner. Furthermore these MSRs, at least on Fam11 and older CPUs, are also consulted by modern Linux, and their (bogus) built-in zapping of #GP faults from MSR accesses leads to it effectively reading zero instead of the intended