Re: query of CP locked guest pages
I should have added that this is how it works in z/VM 5.2.0 and newer releases. z/VM 5.1.0 and older still use the old FRMTE based locking scheme, and there's no host logical / host real differentiation, so there 's only one check, FRMCPLOK. - Bill Holder, z/VM Development, IBM On Fri, 12 Dec 2008 08:33:14 -0600, Bill Holder hold...@us.ibm.com wrot e: Ok, here are the basic steps: - Locate the PTE and PGSTE - If PGSCPLOK=1, the page is locked to real, and if PGSPINCT=1, and PGSOVFLW and PGSOVFL1 are all 0, then you're done. Otherwise, check if the page is (also or instead) locked to logical: - If PGSALIAS=0 or PGSPINCT, PGSOVFL1 and PGSOVFLW are all 0, then the page is not locked to logical. Otherwise, if PGSALIAS=1 and any of PGSPINCT, PGSOVFL1 and PGSOVFLW are not 0, continue: - The valid PTE contains the frame address (PFRA) - Convert the frame address to a FRMTE address (see AEFRM MACRO for the conversion algorithm) - Use FRMTE field FRMSXPN to generate the System Execution Space (Host Logical) page address (tack 8 0 bits on the right). - Convert the SXS page address to the SXS Table Entry (SXSTE) address (see SXSAE MACRO for the conversion algorithm). - If SXSCPLOK=1, the page is locked to logical. I hope that helps. If you're planning on running these structures from outside of CP, say, from another virtual machine, note that they're not completely serialized and actions by the target virtual machine (such as reset, clear, and release functions) can cause pages locked by command to be unlocked and the links between these structures disconnected. - Bill Holder, z/VM Development, IBM
Re: query of CP locked guest pages
thanks - I'll let you know when I get this cookin' David From: The IBM z/VM Operating System on behalf of Bill Holder Sent: Fri 12/12/2008 9:39 AM To: IBMVM@LISTSERV.UARK.EDU Subject: Re: [IBMVM] query of CP locked guest pages I should have added that this is how it works in z/VM 5.2.0 and newer releases. z/VM 5.1.0 and older still use the old FRMTE based locking scheme, and there's no host logical / host real differentiation, so there= 's only one check, FRMCPLOK. - Bill Holder, z/VM Development, IBM On Fri, 12 Dec 2008 08:33:14 -0600, Bill Holder hold...@us.ibm.com wrot= e: Ok, here are the basic steps: - Locate the PTE and PGSTE - If PGSCPLOK=1, the page is locked to real, and if PGSPINCT=1, and PGSOVFLW and PGSOVFL1 are all 0, then you're done. Otherwise, check if the page is (also or instead) locked to logical: - If PGSALIAS=0 or PGSPINCT, PGSOVFL1 and PGSOVFLW are all 0, then the page is not locked to logical. Otherwise, if PGSALIAS=1 and any of PGSPINCT, PGSOVFL1 and PGSOVFLW are not 0, continue: - The valid PTE contains the frame address (PFRA) - Convert the frame address to a FRMTE address (see AEFRM MACRO for the conversion algorithm) - Use FRMTE field FRMSXPN to generate the System Execution Space (Host Logical) page address (tack 8 0 bits on the right). - Convert the SXS page address to the SXS Table Entry (SXSTE) address (see SXSAE MACRO for the conversion algorithm). - If SXSCPLOK=1, the page is locked to logical. I hope that helps. If you're planning on running these structures from outside of CP, say, from another virtual machine, note that they're not completely serialized and actions by the target virtual machine (such as reset, clear, and release functions) can cause pages locked by command to be unlocked and the links between these structures disconnected. - Bill Holder, z/VM Development, IBM
Re: query of CP locked guest pages
The locking / pinning mechanism moved from the FRMTE to the PTE/PGSTE as of 5.2.0 as part of the support for HPMA (a hardware page fault assist allow ing hardware pinning) and QDIO passthrough. A page being locked by command i s now indicated by the PGSCPLOK bit in byte 6 of the PGSTE (see also PGSD98 LK for Diag x'98' locking). Yes, the PGMBK stays resident as long as the page stays locked (in some cases, even after the virtual megabyte has been released). - Bill Holder, z/VM Development, IBM On Thu, 11 Dec 2008 01:05:47 +0100, Rob van der Heij [EMAIL PROTECTED] wrote: On Thu, Dec 11, 2008 at 12:22 AM, David Kreuter [EMAIL PROTECTED] wrote: The frametable entries do not have an obvious bit indicating that the page is a target of a CP lock. I'll keep digging. I'm going to as time permits hunt down through the virtual machine pgm bk's. David So you can tell how long ago it was that I cared. I believe 5.1 still had X'40' as FRMCPLOK My apologies for providing out-of-date guidance. If I have the picture right, then the PGMBK would still be resident as long as one of the pages is resident, even though it now does not live under the bar anymore. -Rob =
Re: query of CP locked guest pages
Dave, are you looking to unlock just a subset of what was locked, or all of them? If you just want to unlock everything, a single UNLOCK command covering all the guest's storage (or two, if pages were explicitly locked to both real and logical) will do it. - Bill Holder, z/VM Development, IBM
Re: query of CP locked guest pages
The other trick I should mention is that PGSCPLOK is only set if the pa ge was explicitly locked to host real. If locked by command to host logical , SXSCPLOK is set in the corresponding SXSTE (another structure entirely, which is used to manage System Execution Space (Host Logical) page usage and mappings). If there is an associated SXSTE (as indicated by PGSALIAS bei ng set), it can be found via the FRMSXPN field in the corresponding FRMTE. So if you know that pages have been locked by CP LOCK, but don't know whethe r they were locked to real or logical or both, you would have to check multiple places to determine whether an individual page was locked by com mand. - Bill Holder, z/VM Development, IBM
Re: query of CP locked guest pages
nah I am in need of a method to determine which pages of a virtual machine have been locked by the lock command. David From: The IBM z/VM Operating System on behalf of Bill Holder Sent: Thu 12/11/2008 12:12 PM To: IBMVM@LISTSERV.UARK.EDU Subject: Re: [IBMVM] query of CP locked guest pages Dave, are you looking to unlock just a subset of what was locked, or all = of them? If you just want to unlock everything, a single UNLOCK command covering all the guest's storage (or two, if pages were explicitly locked= to both real and logical) will do it. - Bill Holder, z/VM Development, IBM
Re: query of CP locked guest pages
On Thursday, 12/11/2008 at 01:32 EST, David Kreuter dkreu...@vm-resources.com wrote: nah I am in need of a method to determine which pages of a virtual machine have been locked by the lock command. Would you use the information for anything other than to unlock said pages? Alan Altmark z/VM Development IBM Endicott
Re: query of CP locked guest pages
There is indeed no CP QUERY LOCKED command, I assume because nobody's ask ed for it before (ok, I haven't actually looked to see if anyone has, it's possible someone did, but it never made the cut). If the information wasn't saved from the point where the LOCK requests were issued, I can't think of anything better than trial and error for doing the UNLOCKs. IND USER will give the number of locked pages (the EXP option will differenti ate locked to real vs. locked to logical), but I'm not aware of anything tha t will provide the addresses of the locked pages. - Bill Holder, z/VM Development, IBM On Wed, 10 Dec 2008 09:47:32 -0600, Dave Jones [EMAIL PROTECTED] wrote: I'm stumped hereI have a guest virtual machine (running Linux, but I think that's immaterial) that has locked some of its pages into host storage via the CP LOCK commandnow I want to find out *which* guest pages were locked. I can find a count of the number of locked pages, but I want to know which ones as well. How come there is no CP QUERY LOCKED command to tell me this? Thanks and have a good one. -- DJ V/Soft z/VM and mainframe Linux expertise, training, consulting, and software development www.vsoft-software.com =
Re: query of CP locked guest pages
On Wed, Dec 10, 2008 at 4:47 PM, Dave Jones [EMAIL PROTECTED] wrote: I'm stumped hereI have a guest virtual machine (running Linux, but I think that's immaterial) that has locked some of its pages into host storage via the CP LOCK commandnow I want to find out *which* guest pages were locked. I can find a count of the number of locked pages, but I want to know which ones as well. No Dave, locked pages is material (i.e. hardware). Unlocked pages are immaterial (virtual) :-) In a former live, in the days that I cared about such things, I had a tiny pipeline stage that could read the core table (using my dcp stage). From there it was trivial to select the entries marked as locked user pages. I used it to determine the reference patterns for Linux pages to decide what portions would be candidates to share. But if your which was only the prelude for the why question: if the guest has a dedicated OSA adapter, then the locked pages are probably the inbound buffers for that. In previous releases the locked pages per guest (under the bar) was part of the motivation to promote virtual network devices. Rob
Re: query of CP locked guest pages
The frametable entries do not have an obvious bit indicating that the page is a target of a CP lock. I'll keep digging. I'm going to as time permits hunt down through the virtual machine pgmbk's. David From: The IBM z/VM Operating System on behalf of Rob van der Heij Sent: Wed 12/10/2008 6:15 PM To: IBMVM@LISTSERV.UARK.EDU Subject: Re: [IBMVM] query of CP locked guest pages On Wed, Dec 10, 2008 at 4:47 PM, Dave Jones [EMAIL PROTECTED] wrote: I'm stumped hereI have a guest virtual machine (running Linux, but I think that's immaterial) that has locked some of its pages into host storage via the CP LOCK commandnow I want to find out *which* guest pages were locked. I can find a count of the number of locked pages, but I want to know which ones as well. No Dave, locked pages is material (i.e. hardware). Unlocked pages are immaterial (virtual) :-) In a former live, in the days that I cared about such things, I had a tiny pipeline stage that could read the core table (using my dcp stage). From there it was trivial to select the entries marked as locked user pages. I used it to determine the reference patterns for Linux pages to decide what portions would be candidates to share. But if your which was only the prelude for the why question: if the guest has a dedicated OSA adapter, then the locked pages are probably the inbound buffers for that. In previous releases the locked pages per guest (under the bar) was part of the motivation to promote virtual network devices. Rob
Re: query of CP locked guest pages
On Thu, Dec 11, 2008 at 12:22 AM, David Kreuter [EMAIL PROTECTED] wrote: The frametable entries do not have an obvious bit indicating that the page is a target of a CP lock. I'll keep digging. I'm going to as time permits hunt down through the virtual machine pgmbk's. David So you can tell how long ago it was that I cared. I believe 5.1 still had X'40' as FRMCPLOK My apologies for providing out-of-date guidance. If I have the picture right, then the PGMBK would still be resident as long as one of the pages is resident, even though it now does not live under the bar anymore. -Rob
Re: query of CP locked guest pages
yearning for the good ole days of yore. The bit has been moved to the PGSTE! That'll take a bit more hunting down - pun intended I suppose - 15160= 15161=* PGSBYTE 6 Additional status bits 15162= 15164=*Bits defined in PGSBYTE6 15166=PGSBYTE6 DSX Byte 6 of page status entry 15167=*PGSCMDLK was FRMCPLOK 15168=PGSCPLOK EQU X'80' A pageable page is locked in th 15169=*frame (pinned) by the CP LOCK 15170=*command, one increment of the 15171=*total pin count represents the 15172=*CP LOCK command lock. David From: The IBM z/VM Operating System on behalf of Rob van der Heij Sent: Wed 12/10/2008 7:05 PM To: IBMVM@LISTSERV.UARK.EDU Subject: Re: [IBMVM] query of CP locked guest pages On Thu, Dec 11, 2008 at 12:22 AM, David Kreuter [EMAIL PROTECTED] wrote: The frametable entries do not have an obvious bit indicating that the page is a target of a CP lock. I'll keep digging. I'm going to as time permits hunt down through the virtual machine pgmbk's. David So you can tell how long ago it was that I cared. I believe 5.1 still had X'40' as FRMCPLOK My apologies for providing out-of-date guidance. If I have the picture right, then the PGMBK would still be resident as long as one of the pages is resident, even though it now does not live under the bar anymore. -Rob
