| Message ID | 1456120999-5639-10-git-send-email-jgross@suse.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Mon, Feb 22, 2016 at 07:03:17AM +0100, Juergen Gross wrote: > Modern pvops linux kernels support an initrd not covered by the initial > mapping. This capability is flagged by an elf-note. > > In case the elf-note is set by the kernel don't place the initrd into > the initial mapping. This will allow to load larger initrds and/or > support domains with larger memory, as the initial mapping is limited > to 2GB and it is containing the p2m list. > > Signed-off-by: Juergen Gross <jgross@suse.com> > Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com> > --- > V4: rename grub_xen_alloc_end() to grub_xen_alloc_final() > --- > grub-core/loader/i386/xen.c | 61 ++++++++++++++++++++++++++++++-------- > grub-core/loader/i386/xen_fileXX.c | 3 ++ > include/grub/xen_file.h | 1 + > 3 files changed, 52 insertions(+), 13 deletions(-) > > diff --git a/grub-core/loader/i386/xen.c b/grub-core/loader/i386/xen.c > index 2e12763..22a94ae 100644 > --- a/grub-core/loader/i386/xen.c > +++ b/grub-core/loader/i386/xen.c > @@ -58,6 +58,7 @@ struct xen_loader_state { > grub_uint64_t modules_target_start; > grub_size_t n_modules; > int loaded; > + int alloc_end_called; alloc_end_called -> alloc_final_called > }; > > static struct xen_loader_state xen_state; > @@ -320,6 +321,28 @@ grub_xen_pt_alloc (void) > } > > static grub_err_t > +grub_xen_alloc_final (void) > +{ > + grub_err_t err; > + > + if (xen_state.alloc_end_called) > + return GRUB_ERR_NONE; > + xen_state.alloc_end_called = 1; This is not nice. What happens if grub_xen_p2m_alloc() allocate what is needed and grub_xen_special_alloc() fails? Maybe grub_xen_p2m_alloc(), grub_xen_special_alloc() and grub_xen_pt_alloc() should check itself that required regions are allocated properly (if (something != NULL)) and do nothing if yes. Daniel
On 22/02/16 09:42, Daniel Kiper wrote: > On Mon, Feb 22, 2016 at 07:03:17AM +0100, Juergen Gross wrote: >> Modern pvops linux kernels support an initrd not covered by the initial >> mapping. This capability is flagged by an elf-note. >> >> In case the elf-note is set by the kernel don't place the initrd into >> the initial mapping. This will allow to load larger initrds and/or >> support domains with larger memory, as the initial mapping is limited >> to 2GB and it is containing the p2m list. >> >> Signed-off-by: Juergen Gross <jgross@suse.com> >> Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com> >> --- >> V4: rename grub_xen_alloc_end() to grub_xen_alloc_final() >> --- >> grub-core/loader/i386/xen.c | 61 ++++++++++++++++++++++++++++++-------- >> grub-core/loader/i386/xen_fileXX.c | 3 ++ >> include/grub/xen_file.h | 1 + >> 3 files changed, 52 insertions(+), 13 deletions(-) >> >> diff --git a/grub-core/loader/i386/xen.c b/grub-core/loader/i386/xen.c >> index 2e12763..22a94ae 100644 >> --- a/grub-core/loader/i386/xen.c >> +++ b/grub-core/loader/i386/xen.c >> @@ -58,6 +58,7 @@ struct xen_loader_state { >> grub_uint64_t modules_target_start; >> grub_size_t n_modules; >> int loaded; >> + int alloc_end_called; > > alloc_end_called -> alloc_final_called > >> }; >> >> static struct xen_loader_state xen_state; >> @@ -320,6 +321,28 @@ grub_xen_pt_alloc (void) >> } >> >> static grub_err_t >> +grub_xen_alloc_final (void) >> +{ >> + grub_err_t err; >> + >> + if (xen_state.alloc_end_called) >> + return GRUB_ERR_NONE; >> + xen_state.alloc_end_called = 1; > > This is not nice. What happens if grub_xen_p2m_alloc() allocate what > is needed and grub_xen_special_alloc() fails? Then grub_xen_alloc_final will fail resulting in boot failure of the new kernel. The memory allocated by the single functions will be freed in case a new boot is attempted (patch 1 and 2). > Maybe grub_xen_p2m_alloc(), grub_xen_special_alloc() and grub_xen_pt_alloc() > should check itself that required regions are allocated properly > (if (something != NULL)) and do nothing if yes. Hmm, with grub_xen_reset() doing appropriate cleanups this would be an option. I think I'll change it as you are suggesting. Juergen
On Mon, Feb 22, 2016 at 10:18:38AM +0100, Juergen Gross wrote: > On 22/02/16 09:42, Daniel Kiper wrote: > > On Mon, Feb 22, 2016 at 07:03:17AM +0100, Juergen Gross wrote: > >> Modern pvops linux kernels support an initrd not covered by the initial > >> mapping. This capability is flagged by an elf-note. > >> > >> In case the elf-note is set by the kernel don't place the initrd into > >> the initial mapping. This will allow to load larger initrds and/or > >> support domains with larger memory, as the initial mapping is limited > >> to 2GB and it is containing the p2m list. > >> > >> Signed-off-by: Juergen Gross <jgross@suse.com> > >> Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com> > >> --- > >> V4: rename grub_xen_alloc_end() to grub_xen_alloc_final() > >> --- > >> grub-core/loader/i386/xen.c | 61 ++++++++++++++++++++++++++++++-------- > >> grub-core/loader/i386/xen_fileXX.c | 3 ++ > >> include/grub/xen_file.h | 1 + > >> 3 files changed, 52 insertions(+), 13 deletions(-) > >> > >> diff --git a/grub-core/loader/i386/xen.c b/grub-core/loader/i386/xen.c > >> index 2e12763..22a94ae 100644 > >> --- a/grub-core/loader/i386/xen.c > >> +++ b/grub-core/loader/i386/xen.c > >> @@ -58,6 +58,7 @@ struct xen_loader_state { > >> grub_uint64_t modules_target_start; > >> grub_size_t n_modules; > >> int loaded; > >> + int alloc_end_called; > > > > alloc_end_called -> alloc_final_called > > > >> }; > >> > >> static struct xen_loader_state xen_state; > >> @@ -320,6 +321,28 @@ grub_xen_pt_alloc (void) > >> } > >> > >> static grub_err_t > >> +grub_xen_alloc_final (void) > >> +{ > >> + grub_err_t err; > >> + > >> + if (xen_state.alloc_end_called) > >> + return GRUB_ERR_NONE; > >> + xen_state.alloc_end_called = 1; > > > > This is not nice. What happens if grub_xen_p2m_alloc() allocate what > > is needed and grub_xen_special_alloc() fails? > > Then grub_xen_alloc_final will fail resulting in boot failure of the > new kernel. The memory allocated by the single functions will be freed > in case a new boot is attempted (patch 1 and 2). > > > Maybe grub_xen_p2m_alloc(), grub_xen_special_alloc() and grub_xen_pt_alloc() > > should check itself that required regions are allocated properly > > (if (something != NULL)) and do nothing if yes. > > Hmm, with grub_xen_reset() doing appropriate cleanups this would be an > option. I think I'll change it as you are suggesting. It looks that we can completely avoid that stuff. I think that grub_xen_alloc_final() should be called conditionally in both places/cases. That is all. Daniel
On 22/02/16 13:24, Daniel Kiper wrote: > On Mon, Feb 22, 2016 at 10:18:38AM +0100, Juergen Gross wrote: >> On 22/02/16 09:42, Daniel Kiper wrote: >>> On Mon, Feb 22, 2016 at 07:03:17AM +0100, Juergen Gross wrote: >>>> Modern pvops linux kernels support an initrd not covered by the initial >>>> mapping. This capability is flagged by an elf-note. >>>> >>>> In case the elf-note is set by the kernel don't place the initrd into >>>> the initial mapping. This will allow to load larger initrds and/or >>>> support domains with larger memory, as the initial mapping is limited >>>> to 2GB and it is containing the p2m list. >>>> >>>> Signed-off-by: Juergen Gross <jgross@suse.com> >>>> Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com> >>>> --- >>>> V4: rename grub_xen_alloc_end() to grub_xen_alloc_final() >>>> --- >>>> grub-core/loader/i386/xen.c | 61 ++++++++++++++++++++++++++++++-------- >>>> grub-core/loader/i386/xen_fileXX.c | 3 ++ >>>> include/grub/xen_file.h | 1 + >>>> 3 files changed, 52 insertions(+), 13 deletions(-) >>>> >>>> diff --git a/grub-core/loader/i386/xen.c b/grub-core/loader/i386/xen.c >>>> index 2e12763..22a94ae 100644 >>>> --- a/grub-core/loader/i386/xen.c >>>> +++ b/grub-core/loader/i386/xen.c >>>> @@ -58,6 +58,7 @@ struct xen_loader_state { >>>> grub_uint64_t modules_target_start; >>>> grub_size_t n_modules; >>>> int loaded; >>>> + int alloc_end_called; >>> >>> alloc_end_called -> alloc_final_called >>> >>>> }; >>>> >>>> static struct xen_loader_state xen_state; >>>> @@ -320,6 +321,28 @@ grub_xen_pt_alloc (void) >>>> } >>>> >>>> static grub_err_t >>>> +grub_xen_alloc_final (void) >>>> +{ >>>> + grub_err_t err; >>>> + >>>> + if (xen_state.alloc_end_called) >>>> + return GRUB_ERR_NONE; >>>> + xen_state.alloc_end_called = 1; >>> >>> This is not nice. What happens if grub_xen_p2m_alloc() allocate what >>> is needed and grub_xen_special_alloc() fails? >> >> Then grub_xen_alloc_final will fail resulting in boot failure of the >> new kernel. The memory allocated by the single functions will be freed >> in case a new boot is attempted (patch 1 and 2). >> >>> Maybe grub_xen_p2m_alloc(), grub_xen_special_alloc() and grub_xen_pt_alloc() >>> should check itself that required regions are allocated properly >>> (if (something != NULL)) and do nothing if yes. >> >> Hmm, with grub_xen_reset() doing appropriate cleanups this would be an >> option. I think I'll change it as you are suggesting. > > It looks that we can completely avoid that stuff. I think that > grub_xen_alloc_final() should be called conditionally in both > places/cases. That is all. Hmm. I think this is less clear, especially taking patch 11 into account. And I wouldn't like to tie e.g. page table allocation to something like "if (!xen_state.virt_start_info)" which would result from that change, now that I've removed xen_state.alloc_end_called as you suggested. Juergen
diff --git a/grub-core/loader/i386/xen.c b/grub-core/loader/i386/xen.c index 2e12763..22a94ae 100644 --- a/grub-core/loader/i386/xen.c +++ b/grub-core/loader/i386/xen.c @@ -58,6 +58,7 @@ struct xen_loader_state { grub_uint64_t modules_target_start; grub_size_t n_modules; int loaded; + int alloc_end_called; }; static struct xen_loader_state xen_state; @@ -320,6 +321,28 @@ grub_xen_pt_alloc (void) } static grub_err_t +grub_xen_alloc_final (void) +{ + grub_err_t err; + + if (xen_state.alloc_end_called) + return GRUB_ERR_NONE; + xen_state.alloc_end_called = 1; + + err = grub_xen_p2m_alloc (); + if (err) + return err; + err = grub_xen_special_alloc (); + if (err) + return err; + err = grub_xen_pt_alloc (); + if (err) + return err; + + return GRUB_ERR_NONE; +} + +static grub_err_t grub_xen_boot (void) { grub_err_t err; @@ -330,13 +353,7 @@ grub_xen_boot (void) if (grub_xen_n_allocated_shared_pages) return grub_error (GRUB_ERR_BUG, "active grants"); - err = grub_xen_p2m_alloc (); - if (err) - return err; - err = grub_xen_special_alloc (); - if (err) - return err; - err = grub_xen_pt_alloc (); + err = grub_xen_alloc_final (); if (err) return err; @@ -610,6 +627,13 @@ grub_cmd_initrd (grub_command_t cmd __attribute__ ((unused)), goto fail; } + if (xen_state.xen_inf.unmapped_initrd) + { + err = grub_xen_alloc_final (); + if (err) + goto fail; + } + if (grub_initrd_init (argc, argv, &initrd_ctx)) goto fail; @@ -627,14 +651,24 @@ grub_cmd_initrd (grub_command_t cmd __attribute__ ((unused)), goto fail; } - xen_state.next_start.mod_start = - xen_state.max_addr + xen_state.xen_inf.virt_base; - xen_state.next_start.mod_len = size; - - xen_state.max_addr = ALIGN_UP (xen_state.max_addr + size, PAGE_SIZE); + if (xen_state.xen_inf.unmapped_initrd) + { + xen_state.next_start.flags |= SIF_MOD_START_PFN; + xen_state.next_start.mod_start = xen_state.max_addr >> PAGE_SHIFT; + xen_state.next_start.mod_len = size; + } + else + { + xen_state.next_start.mod_start = + xen_state.max_addr + xen_state.xen_inf.virt_base; + xen_state.next_start.mod_len = size; + } grub_dprintf ("xen", "Initrd, addr=0x%x, size=0x%x\n", - (unsigned) xen_state.next_start.mod_start, (unsigned) size); + (unsigned) (xen_state.max_addr + xen_state.xen_inf.virt_base), + (unsigned) size); + + xen_state.max_addr = ALIGN_UP (xen_state.max_addr + size, PAGE_SIZE); fail: grub_initrd_close (&initrd_ctx); @@ -686,6 +720,7 @@ grub_cmd_module (grub_command_t cmd __attribute__ ((unused)), if (!xen_state.module_info_page) { + xen_state.xen_inf.unmapped_initrd = 0; xen_state.n_modules = 0; xen_state.max_addr = ALIGN_UP (xen_state.max_addr, PAGE_SIZE); xen_state.modules_target_start = xen_state.max_addr; diff --git a/grub-core/loader/i386/xen_fileXX.c b/grub-core/loader/i386/xen_fileXX.c index 1f7f71d..d68634d 100644 --- a/grub-core/loader/i386/xen_fileXX.c +++ b/grub-core/loader/i386/xen_fileXX.c @@ -259,6 +259,9 @@ parse_note (grub_elf_t elf, struct grub_xen_file_info *xi, descsz == 2 ? 2 : 3) == 0) xi->arch = GRUB_XEN_FILE_I386; break; + case XEN_ELFNOTE_MOD_START_PFN: + xi->unmapped_initrd = !!grub_le_to_cpu32(*(grub_uint32_t *) desc); + break; default: grub_dprintf ("xen", "unknown note type %d\n", nh->n_type); break; diff --git a/include/grub/xen_file.h b/include/grub/xen_file.h index 4b2ccba..ed749fa 100644 --- a/include/grub/xen_file.h +++ b/include/grub/xen_file.h @@ -36,6 +36,7 @@ struct grub_xen_file_info int has_note; int has_xen_guest; int extended_cr3; + int unmapped_initrd; enum { GRUB_XEN_FILE_I386 = 1,