smp booting query hi all, My query is related to xen-3.0.3. 1. Xen does not supports SMP booting , right? Is it true for both domU and dom0? 2. This means start_secondary from x86_32.S is never called by the hypervisor, am i right? the SECONDARY_CPU_FLAG denotes a non boot CPU here i guess? 3. If it is a secondary processor xen jumps to start_secondary. 4. __start_xen is called irrespective of the processor. right? 5. On doing a nm x86_32.o , we get - U __bss_start 00000057 t __start U __start_xen U _end 00000000 T _stext 00000000 B cpu0_stack 000001ac T gdt 000001aa t gdt_descr 00001000 T gdt_table 00000000 B idle_pg_table 00000000 B idle_pg_table_l2 000001a4 T idt 000001a2 t idt_descr U idt_table 00000170 t ignore_int 0000015c t int_msg U mmu_cr4_features 000001b2 t nopaging_gdt_descr 00000031 t not_multiboot 00000010 t not_multiboot_msg U printf 00000190 T stack_start 00000000 T start 00000108 t start_paging U start_secondary 00000000 T stext nm shows that start_secondary is there still.Are we using it somehow ? or am i missing something here? Thanks in advance? ----------------------- Pradeep Singh Member Technical Staff Core Technology Divison 53, Greams Road. HCL Technologies, Chennai DISCLAIMER: ----------------------------------------------------------------------------------------------------------------------- The contents of this e-mail and any attachment(s) are confidential and intended for the named recipient(s) only. It shall not attach any liability on the originator or HCL or its affiliates. Any views or opinions presented in this email are solely those of the author and may not necessarily reflect the opinions of HCL or its affiliates. Any form of reproduction, dissemination, copying, disclosure, modification, distribution and / or publication of this message without the prior written consent of the author of this e-mail is strictly prohibited. If you have received this email in error please delete it and notify the sender immediately. Before opening any mail and attachments please check them for viruses and defect. ----------------------------------------------------------------------------------------------------------------------- _______________________________________________ Xen-devel mailing list Xen-devel@lists.xensource.com http://lists.xensource.com/xen-devel
> -----Original Message----- > From: xen-devel-bounces@lists.xensource.com > [mailto:xen-devel-bounces@lists.xensource.com] On Behalf Of > Pradeep Singh, TLS-Chennai > Sent: 09 March 2007 13:27 > To: xen-devel@lists.xensource.com > Subject: [Xen-devel] smp booting query > > > hi all, > > My query is related to xen-3.0.3. > > 1. Xen does not supports SMP booting , right? > Is it true for both domU and dom0?I''m pretty sure that 3.0.3 supports SMP in boht Dom0 and para-virtual DomU. It also supports SMP in HVM DomU, but I''m not sure how "automatic" this support is (there were some changes recently to fix ACPI information to tell the guest how many CPU''s it''s got, for example).> > 2. This means start_secondary from x86_32.S is never called > by the hypervisor, am i right? > the SECONDARY_CPU_FLAG denotes a non boot CPU here i guess?Why do you think this?> > 3. If it is a secondary processor xen jumps to start_secondary.Yes.> > 4. __start_xen is called irrespective of the processor. right?No, only on the first CPU, not other CPU''s.> > 5. On doing a nm x86_32.o , we get - > > U __bss_start > 00000057 t __start > U __start_xen > U _end > 00000000 T _stext > 00000000 B cpu0_stack > 000001ac T gdt > 000001aa t gdt_descr > 00001000 T gdt_table > 00000000 B idle_pg_table > 00000000 B idle_pg_table_l2 > 000001a4 T idt > 000001a2 t idt_descr > U idt_table > 00000170 t ignore_int > 0000015c t int_msg > U mmu_cr4_features > 000001b2 t nopaging_gdt_descr > 00000031 t not_multiboot > 00000010 t not_multiboot_msg > U printf > 00000190 T stack_start > 00000000 T start > 00000108 t start_paging > U start_secondary > 00000000 T stext > > nm shows that start_secondary is there still.Are we using it somehow ?Yes, on booting the second and further procesors... -- Mats> > or am i missing something here? > > Thanks in advance? > > > > > ----------------------- > Pradeep Singh > Member Technical Staff > Core Technology Divison > 53, Greams Road. > HCL Technologies, Chennai > > > >_______________________________________________ Xen-devel mailing list Xen-devel@lists.xensource.com http://lists.xensource.com/xen-devel
On Friday 09 March 2007 13:40, Petersson, Mats wrote:> > -----Original Message----- > > From: xen-devel-bounces@lists.xensource.com > > [mailto:xen-devel-bounces@lists.xensource.com] On Behalf Of > > Pradeep Singh, TLS-Chennai > > Sent: 09 March 2007 13:27 > > To: xen-devel@lists.xensource.com > > Subject: [Xen-devel] smp booting query > > > > > > hi all, > > > > My query is related to xen-3.0.3. > > > > 1. Xen does not supports SMP booting , right? > > Is it true for both domU and dom0? > > I''m pretty sure that 3.0.3 supports SMP in boht Dom0 and para-virtual > DomU.Yep. The entire 3.x.y series has supported SMP domUs and dom0 (although dom0 SMP is not the recommended way of doing things). There are occasional documents floating round on the web saying that "Xen" only supports SMP hosts and not SMP guests - these mostly date back to the Xen 1 and Xen 2 series (or are referring to pre-3.0.3 HVM support which was UP only) Hope that helps clarify the current state for you Pradeep. Cheers, Mark> It also supports SMP in HVM DomU, but I''m not sure how "automatic" > this support is (there were some changes recently to fix ACPI > information to tell the guest how many CPU''s it''s got, for example). > > > 2. This means start_secondary from x86_32.S is never called > > by the hypervisor, am i right? > > the SECONDARY_CPU_FLAG denotes a non boot CPU here i guess? > > Why do you think this? > > > 3. If it is a secondary processor xen jumps to start_secondary. > > Yes. > > > 4. __start_xen is called irrespective of the processor. right? > > No, only on the first CPU, not other CPU''s. > > > 5. On doing a nm x86_32.o , we get - > > > > U __bss_start > > 00000057 t __start > > U __start_xen > > U _end > > 00000000 T _stext > > 00000000 B cpu0_stack > > 000001ac T gdt > > 000001aa t gdt_descr > > 00001000 T gdt_table > > 00000000 B idle_pg_table > > 00000000 B idle_pg_table_l2 > > 000001a4 T idt > > 000001a2 t idt_descr > > U idt_table > > 00000170 t ignore_int > > 0000015c t int_msg > > U mmu_cr4_features > > 000001b2 t nopaging_gdt_descr > > 00000031 t not_multiboot > > 00000010 t not_multiboot_msg > > U printf > > 00000190 T stack_start > > 00000000 T start > > 00000108 t start_paging > > U start_secondary > > 00000000 T stext > > > > nm shows that start_secondary is there still.Are we using it somehow ? > > Yes, on booting the second and further procesors... > > -- > Mats > > > or am i missing something here? > > > > Thanks in advance? > > > > > > > > > > ----------------------- > > Pradeep Singh > > Member Technical Staff > > Core Technology Divison > > 53, Greams Road. > > HCL Technologies, Chennai > > _______________________________________________ > Xen-devel mailing list > Xen-devel@lists.xensource.com > http://lists.xensource.com/xen-devel-- Dave: Just a question. What use is a unicyle with no seat? And no pedals! Mark: To answer a question with a question: What use is a skateboard? Dave: Skateboards have wheels. Mark: My wheel has a wheel! _______________________________________________ Xen-devel mailing list Xen-devel@lists.xensource.com http://lists.xensource.com/xen-devel
RE: [Xen-devel] smp booting query -----Original Message----- From: M.A. Williamson on behalf of Mark Williamson Sent: Sun 11-Mar-07 9:28 AM To: xen-devel@lists.xensource.com Cc: Petersson, Mats; Pradeep Singh, TLS-Chennai Subject: Re: [Xen-devel] smp booting query On Friday 09 March 2007 13:40, Petersson, Mats wrote: > > -----Original Message----- > > From: xen-devel-bounces@lists.xensource.com > > [mailto:xen-devel-bounces@lists.xensource.com] On Behalf Of > > Pradeep Singh, TLS-Chennai > > Sent: 09 March 2007 13:27 > > To: xen-devel@lists.xensource.com > > Subject: [Xen-devel] smp booting query > > > > > > hi all, > > > > My query is related to xen-3.0.3. > > > > 1. Xen does not supports SMP booting , right? > > Is it true for both domU and dom0? > > I''m pretty sure that 3.0.3 supports SMP in boht Dom0 and para-virtual > DomU. Yep. The entire 3.x.y series has supported SMP domUs and dom0 (although dom0 SMP is not the recommended way of doing things). There are occasional documents floating round on the web saying that "Xen" only supports SMP hosts and not SMP guests - these mostly date back to the Xen 1 and Xen 2 series (or are referring to pre-3.0.3 HVM support which was UP only) Hope that helps clarify the current state for you Pradeep. Thanks Mark, definitely this cleared my doubt. Thank you all. pradeep Cheers, Mark > It also supports SMP in HVM DomU, but I''m not sure how "automatic" > this support is (there were some changes recently to fix ACPI > information to tell the guest how many CPU''s it''s got, for example). > > > 2. This means start_secondary from x86_32.S is never called > > by the hypervisor, am i right? > > the SECONDARY_CPU_FLAG denotes a non boot CPU here i guess? > > Why do you think this? > > > 3. If it is a secondary processor xen jumps to start_secondary. > > Yes. > > > 4. __start_xen is called irrespective of the processor. right? > > No, only on the first CPU, not other CPU''s. > > > 5. On doing a nm x86_32.o , we get - > > > > U __bss_start > > 00000057 t __start > > U __start_xen > > U _end > > 00000000 T _stext > > 00000000 B cpu0_stack > > 000001ac T gdt > > 000001aa t gdt_descr > > 00001000 T gdt_table > > 00000000 B idle_pg_table > > 00000000 B idle_pg_table_l2 > > 000001a4 T idt > > 000001a2 t idt_descr > > U idt_table > > 00000170 t ignore_int > > 0000015c t int_msg > > U mmu_cr4_features > > 000001b2 t nopaging_gdt_descr > > 00000031 t not_multiboot > > 00000010 t not_multiboot_msg > > U printf > > 00000190 T stack_start > > 00000000 T start > > 00000108 t start_paging > > U start_secondary > > 00000000 T stext > > > > nm shows that start_secondary is there still.Are we using it somehow ? > > Yes, on booting the second and further procesors... > > -- > Mats > > > or am i missing something here? > > > > Thanks in advance? > > > > > > > > > > ----------------------- > > Pradeep Singh > > Member Technical Staff > > Core Technology Divison > > 53, Greams Road. > > HCL Technologies, Chennai > > _______________________________________________ > Xen-devel mailing list > Xen-devel@lists.xensource.com > http://lists.xensource.com/xen-devel -- Dave: Just a question. What use is a unicyle with no seat? And no pedals! Mark: To answer a question with a question: What use is a skateboard? Dave: Skateboards have wheels. Mark: My wheel has a wheel! DISCLAIMER: ----------------------------------------------------------------------------------------------------------------------- The contents of this e-mail and any attachment(s) are confidential and intended for the named recipient(s) only. It shall not attach any liability on the originator or HCL or its affiliates. Any views or opinions presented in this email are solely those of the author and may not necessarily reflect the opinions of HCL or its affiliates. Any form of reproduction, dissemination, copying, disclosure, modification, distribution and / or publication of this message without the prior written consent of the author of this e-mail is strictly prohibited. If you have received this email in error please delete it and notify the sender immediately. Before opening any mail and attachments please check them for viruses and defect. ----------------------------------------------------------------------------------------------------------------------- _______________________________________________ Xen-devel mailing list Xen-devel@lists.xensource.com http://lists.xensource.com/xen-devel