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On Tue, Jul 14, 2020 at 02:08:47PM +0200, Joerg Roedel wrote: > @@ -489,6 +490,9 @@ DEFINE_IDTENTRY_RAW(exc_nmi) > this_cpu_write(nmi_cr2, read_cr2()); > nmi_restart: > > + /* Needs to happen before DR7 is accessed */ > + sev_es_ist_enter(regs); > + > this_cpu_write(nmi_dr7, local_db_save()); > > nmi_enter(); > @@ -502,6 +506,8 @@

On Tue, Jul 14, 2020 at 02:08:47PM +0200, Joerg Roedel wrote: > @@ -489,6 +490,9 @@ DEFINE_IDTENTRY_RAW(exc_nmi) > this_cpu_write(nmi_cr2, read_cr2()); > nmi_restart: > > + /* Needs to happen before DR7 is accessed */ > + sev_es_ist_enter(regs); > + > this_cpu_write(nmi_dr7, local_db_save()); > > nmi_enter(); > @@ -502,6 +506,8 @@

Hi Andy, On Mon, Apr 27, 2020 at 10:37:41AM -0700, Andy Lutomirski wrote: > 1. Use IST for #VC and deal with all the mess that entails. With the removal of IST shifting I wonder what you would suggest on how to best implement an NMI-safe IST handler with nesting support. My current plan is to implement an IST handler which switches itself off the IST stack as soon as possible, freeing it for

Dear All, I have configured Cluster Suite with 2 servers Server 1 : 192.168.13.110 IP Address Server 2 : 192.168.13.179 IP Address Floating : 192.168.13.83 IP Address (Assumed by currently active server) I want all snmp packets going out through the active server to be stamped with floating IP So i have added a iptables rules as "iptables -t nat -A POSTROUTING -p udp -s

On Wed, Jul 15, 2020 at 11:47:02AM +0200, Peter Zijlstra wrote: > On Tue, Jul 14, 2020 at 02:08:47PM +0200, Joerg Roedel wrote: > DECLARE_STATIC_KEY_FALSE(sev_es_enabled_key); > > static __always_inline void sev_es_foo() > { > if (static_branch_unlikely(&sev_es_enabled_key)) > __sev_es_foo(); > } > > So that normal people will only see an extra NOP? Yes,

On Sat, Apr 25, 2020 at 1:23 PM Joerg Roedel <joro at 8bytes.org> wrote: > > On Sat, Apr 25, 2020 at 12:47:31PM -0700, Andy Lutomirski wrote: > > I assume the race you mean is: > > > > #VC > > Immediate NMI before IST gets shifted > > #VC > > > > Kaboom. > > > > How are you dealing with this? Ultimately, I think that NMI will need

On Mon, Apr 27, 2020 at 10:37:41AM -0700, Andy Lutomirski wrote: > I have a somewhat serious question: should we use IST for #VC at all? > As I understand it, Rome and Naples make it mandatory for hypervisors > to intercept #DB, which means that, due to the MOV SS mess, it's sort > of mandatory to use IST for #VC. But Milan fixes the #DB issue, so, > if we're running under

From: Joerg Roedel <jroedel at suse.de> When an NMI hits in the #VC handler entry code before it switched to another stack, any subsequent #VC exception in the NMI code-path will overwrite the interrupted #VC handlers stack. Make sure this doesn't happen by explicitly adjusting the #VC IST entry in the NMI handler for the time in can cause #VC exceptions. Signed-off-by: Joerg Roedel

On Tue, Jun 23, 2020 at 11:45:19AM +0200, Joerg Roedel wrote: > Hi Andy, > > On Mon, Apr 27, 2020 at 10:37:41AM -0700, Andy Lutomirski wrote: > > 1. Use IST for #VC and deal with all the mess that entails. > > With the removal of IST shifting I wonder what you would suggest on how > to best implement an NMI-safe IST handler with nesting support. > > My current plan

From: Joerg Roedel <jroedel at suse.de> Allocate and map enough stacks for the #VC handler to support sufficient levels of nesting and the NMI-in-#VC scenario. Also setup the IST entrys for the #VC handler on all CPUs because #VC needs to work before cpu_init() has set up the per-cpu TSS. Signed-off-by: Joerg Roedel <jroedel at suse.de> --- arch/x86/include/asm/cpu_entry_area.h |

From: Joerg Roedel <jroedel at suse.de> When an NMI hits in the #VC handler entry code before it switched to another stack, any subsequent #VC exception in the NMI code-path will overwrite the interrupted #VC handlers stack. Make sure this doesn't happen by explicitly adjusting the #VC IST entry in the NMI handler for the time in can cause #VC exceptions. Signed-off-by: Joerg Roedel

On Tue, Jun 23, 2020 at 01:50:14PM +0200, Peter Zijlstra wrote: > If SNP is the sole reason #VC needs to be IST, then I'd strongly urge > you to only make it IST if/when you try and make SNP happen, not before. It is not the only reason, when ES guests gain debug register support then #VC also needs to be IST, because #DB can be promoted into #VC then, and as #DB is IST for a reason,

Hi Peter, On Tue, Jun 23, 2020 at 12:45:59PM +0200, Peter Zijlstra wrote: > On Tue, Jun 23, 2020 at 11:45:19AM +0200, Joerg Roedel wrote: > > Or maybe you have a better idea how to implement this, so I'd like to > > hear your opinion first before I spend too many days implementing > > something. > > OK, excuse my ignorance, but I'm not seeing how that IST

Dear all, I have installed Samba (3.6.6) on Debian wheezy and configured it to authenticate against LDAP (encrypted passwords, no lanman). I want simple shares with user security. I have configured PAM/NSS from the same LDAP and it works fine. WinXP works fine, smbclient works fine, but Windows 7 only works for SOME passwords. Some work, some do not. Samba is configured with restricted LDAP

On Tue, Jun 23, 2020 at 01:14:43PM +0200, Peter Zijlstra wrote: > On Tue, Jun 23, 2020 at 01:11:07PM +0200, Joerg Roedel wrote: > > The v3 patchset implements an unconditional shift of the #VC IST entry > > in the NMI handler, before it can trigger a #VC exception. > > Going by that other thread -- where you said that any memory access can > trigger a #VC, there just

Sometime my mongrel server threads..would simply stop responding to the requests...and in the logs i get following error: Tue Sep 05 03:56:40 IST 2006: ERROR: Transport endpoint is not connected - getpeername(2) Tue Sep 05 03:59:21 IST 2006: ERROR: Transport endpoint is not connected - getpeername(2) Tue Sep 05 03:59:21 IST 2006: ERROR: Transport endpoint is not connected - getpeername(2) Tue Sep

Hallo Liste Derzeit mache ich meine ersten Gehversuche mit Linux (SuSE). Bis jetzt habe ich in einem kleinen Netzwerk f?r meine Tauchschule vier Rechner betreut. Einer davon war WinNT-4.0 Server und Arbeitsplatz zugleich. Nachdem ich nicht mehr bereit bin, mich mit dem w?chentlichen "blue screen" und dem monatlichen Neuinstallieren von NT abzufinden, bin ich derzeit beim Umsteigen auf

On Tue, Jun 23, 2020 at 01:48:18PM +0200, Peter Zijlstra wrote: > On Tue, Jun 23, 2020 at 01:30:07PM +0200, Joerg Roedel wrote: > But you cannot do a recursion check in #VC, because the NMI can happen > on the first instruction of #VC, before we can increment our counter, > and then the #VC can happen on NMI because the IST stack is a goner, and > we're fscked again (or on a

On Tue, Jun 23, 2020 at 03:03:22PM +0200, Peter Zijlstra wrote: > On Tue, Jun 23, 2020 at 02:12:37PM +0200, Joerg Roedel wrote: > > On Tue, Jun 23, 2020 at 01:50:14PM +0200, Peter Zijlstra wrote: > > > If SNP is the sole reason #VC needs to be IST, then I'd strongly urge > > > you to only make it IST if/when you try and make SNP happen, not before. > > >

On Sat, Apr 25, 2020 at 3:10 PM Andy Lutomirski <luto at kernel.org> wrote: > > On Sat, Apr 25, 2020 at 1:23 PM Joerg Roedel <joro at 8bytes.org> wrote: > > > > On Sat, Apr 25, 2020 at 12:47:31PM -0700, Andy Lutomirski wrote: > > > I assume the race you mean is: > > > > > > #VC > > > Immediate NMI before IST gets shifted > >