Re: [Crash-utility] Fix pvops Xen detection for kernels >= v4.20

-----Original Message----- > Kernel commit 5c83511bdb9832c86be20fb86b783356e2f58062 removed > pv_init_ops, and later commit 054ac8ad5ebe4a69e1f0e842483821ddbe560121 > removed the Xen-specific paravirt patch function. As a result, pvops Xen > dumps are no longer recognized as Xen dumps, and virtual-to-physical > translation fails. > > Use the value of xen_start_info to determine whether the kernel is > running in Xen PV mode. This pointer is set during the initialization of > a PV domain. Kudos to Juergen Gross, who suggested this check. > > Signed-off-by: Petr Tesarik <ptesarik(a)suse.com&gt; Thank you, the patch looks good to me. Acked-by: Kazuhito Hagio <k-hagio-ab(a)nec.com&gt; Lianbo, the patch needs some space adjustment to apply, here is a modified patch: https://github.com/k-hagio/crash/commit/a7d5cd4169a994b1faa1f646c149d1f54...

Kazu > --- > kernel.c | 34 ++++++++++++++++++++++++++++------ > 1 file changed, 28 insertions(+), 6 deletions(-) > > diff --git a/kernel.c b/kernel.c > index e123f76..36fdea2 100644 > --- a/kernel.c > +++ b/kernel.c > @@ -95,6 +95,7 @@ static ulong __dump_audit(char *); > static void dump_audit(void); > static char *vmcoreinfo_read_string(const char *); > static void check_vmcoreinfo(void); > +static int is_pvops_xen(void); > > > /* > @@ -109,7 +110,6 @@ kernel_init() > char *rqstruct; > char *rq_timestamp_name = NULL; > char *irq_desc_type_name; > - ulong pv_init_ops; > struct gnu_request req; > > if (pc->flags & KERNEL_DEBUG_QUERY) > @@ -169,11 +169,7 @@ kernel_init() > error(FATAL, "cannot malloc m2p page."); > } > > - if (PVOPS() && symbol_exists("pv_init_ops") && > - readmem(symbol_value("pv_init_ops"), KVADDR, &pv_init_ops, > - sizeof(void *), "pv_init_ops", RETURN_ON_ERROR) && > - ((p1 = value_symbol(pv_init_ops)) && > - (STREQ(p1, "xen_patch") || STREQ(p1, "paravirt_patch_default")))) { > + if (is_pvops_xen()) { > kt->flags |= ARCH_XEN | ARCH_PVOPS_XEN; > kt->xen_flags |= WRITABLE_PAGE_TABLES; > if (machine_type("X86")) > @@ -10709,6 +10705,32 @@ paravirt_init(void) > } > } > > +static int > +is_pvops_xen(void) > +{ > + ulong addr; > + char *sym; > + > + if (!PVOPS()) > + return FALSE; > + > + if (symbol_exists("pv_init_ops") && > + readmem(symbol_value("pv_init_ops"), KVADDR, &addr, > + sizeof(void *), "pv_init_ops", RETURN_ON_ERROR) && > + (sym = value_symbol(addr)) && > + (STREQ(sym, "xen_patch") || > + STREQ(sym, "paravirt_patch_default"))) > + return TRUE; > + > + if (symbol_exists("xen_start_info") && > + readmem(symbol_value("xen_start_info"), KVADDR, &addr, > + sizeof(void *), "xen_start_info", RETURN_ON_ERROR) && > + addr != 0) > + return TRUE; > + > + return FALSE; > +} > + > /* > * Get the kernel's xtime timespec from its relevant location. > */ > > > -- > Crash-utility mailing list > Crash-utility(a)redhat.com > https://listman.redhat.com/mailman/listinfo/crash-utility