Date: Sun, 26 Aug 2018 20:55:06 +0000 From: Colin Percival <cperciva@tarsnap.com> To: =?UTF-8?Q?Roger_Pau_Monn=c3=a9?= <royger@FreeBSD.org>, src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org Subject: Re: svn commit: r335668 - head/sys/x86/xen Message-ID: <010001657804d39a-54227e19-0fac-430f-9574-f83e225afb47-000000@email.amazonses.com> In-Reply-To: <201806261500.w5QF0s1I071232@repo.freebsd.org> References: <201806261500.w5QF0s1I071232@repo.freebsd.org>
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This breaks the kernel boot in EC2 Xen-based instances; it now hangs in the taskqgroup_adjust_if_io_tqg SYSINIT. I've attached a verbose dmesg from r335666 in case that helps you figure out what's going on. My guess is that EC2 is numbering virtual CPUs oddly -- but regardless of the cause, this definitely needs to be fixed. Colin Percival On 6/26/18 8:00 AM, Roger Pau Monné wrote: > Author: royger > Date: Tue Jun 26 15:00:54 2018 > New Revision: 335668 > URL: https://svnweb.freebsd.org/changeset/base/335668 > > Log: > xen: obtain vCPU ID from CPUID > > The Xen vCPU ID can be fetched from the cpuid instead of inferring it > from the ACPI ID. > > Sponsored by: Citrix Systems R&D > > Modified: > head/sys/x86/xen/hvm.c > > Modified: head/sys/x86/xen/hvm.c > ============================================================================== > --- head/sys/x86/xen/hvm.c Tue Jun 26 14:48:23 2018 (r335667) > +++ head/sys/x86/xen/hvm.c Tue Jun 26 15:00:54 2018 (r335668) > @@ -56,6 +56,7 @@ __FBSDID("$FreeBSD$"); > #include <xen/hvm.h> > #include <xen/xen_intr.h> > > +#include <xen/interface/arch-x86/cpuid.h> > #include <xen/interface/hvm/params.h> > #include <xen/interface/vcpu.h> > > @@ -103,6 +104,9 @@ TUNABLE_INT("hw.xen.disable_pv_disks", &xen_disable_pv > TUNABLE_INT("hw.xen.disable_pv_nics", &xen_disable_pv_nics); > > /*---------------------- XEN Hypervisor Probe and Setup ----------------------*/ > + > +static uint32_t cpuid_base; > + > static uint32_t > xen_hvm_cpuid_base(void) > { > @@ -123,21 +127,21 @@ xen_hvm_cpuid_base(void) > static int > xen_hvm_init_hypercall_stubs(enum xen_hvm_init_type init_type) > { > - uint32_t base, regs[4]; > + uint32_t regs[4]; > > if (xen_pv_domain()) { > /* hypercall page is already set in the PV case */ > return (0); > } > > - base = xen_hvm_cpuid_base(); > - if (base == 0) > + cpuid_base = xen_hvm_cpuid_base(); > + if (cpuid_base == 0) > return (ENXIO); > > if (init_type == XEN_HVM_INIT_COLD) { > int major, minor; > > - do_cpuid(base + 1, regs); > + do_cpuid(cpuid_base + 1, regs); > > major = regs[0] >> 16; > minor = regs[0] & 0xffff; > @@ -165,7 +169,7 @@ xen_hvm_init_hypercall_stubs(enum xen_hvm_init_type in > /* > * Find the hypercall pages. > */ > - do_cpuid(base + 2, regs); > + do_cpuid(cpuid_base + 2, regs); > if (regs[0] != 1) > return (EINVAL); > > @@ -371,31 +375,14 @@ xen_hvm_sysinit(void *arg __unused) > { > xen_hvm_init(XEN_HVM_INIT_COLD); > } > +SYSINIT(xen_hvm_init, SI_SUB_HYPERVISOR, SI_ORDER_FIRST, xen_hvm_sysinit, NULL); > > static void > -xen_set_vcpu_id(void) > -{ > - struct pcpu *pc; > - int i; > - > - if (!xen_hvm_domain()) > - return; > - > - /* Set vcpu_id to acpi_id */ > - CPU_FOREACH(i) { > - pc = pcpu_find(i); > - pc->pc_vcpu_id = pc->pc_acpi_id; > - if (bootverbose) > - printf("XEN: CPU %u has VCPU ID %u\n", > - i, pc->pc_vcpu_id); > - } > -} > - > -static void > xen_hvm_cpu_init(void) > { > struct vcpu_register_vcpu_info info; > struct vcpu_info *vcpu_info; > + uint32_t regs[4]; > int cpu, rc; > > if (!xen_domain()) > @@ -410,6 +397,22 @@ xen_hvm_cpu_init(void) > return; > } > > + /* > + * Set vCPU ID. If available fetch the ID from CPUID, if not just use > + * the ACPI ID. > + */ > + KASSERT(cpuid_base != 0, ("Invalid base Xen CPUID leaf")); > + cpuid_count(cpuid_base + 4, 0, regs); > + PCPU_SET(vcpu_id, (regs[0] & XEN_HVM_CPUID_VCPU_ID_PRESENT) ? > + regs[1] : PCPU_GET(acpi_id)); > + > + /* > + * Set the vCPU info. > + * > + * NB: the vCPU info for vCPUs < 32 can be fetched from the shared info > + * page, but in order to make sure the mapping code is correct always > + * attempt to map the vCPU info at a custom place. > + */ > vcpu_info = DPCPU_PTR(vcpu_local_info); > cpu = PCPU_GET(vcpu_id); > info.mfn = vtophys(vcpu_info) >> PAGE_SHIFT; > @@ -421,7 +424,4 @@ xen_hvm_cpu_init(void) > else > DPCPU_SET(vcpu_info, vcpu_info); > } > - > -SYSINIT(xen_hvm_init, SI_SUB_HYPERVISOR, SI_ORDER_FIRST, xen_hvm_sysinit, NULL); > SYSINIT(xen_hvm_cpu_init, SI_SUB_INTR, SI_ORDER_FIRST, xen_hvm_cpu_init, NULL); > -SYSINIT(xen_set_vcpu_id, SI_SUB_CPU, SI_ORDER_ANY, xen_set_vcpu_id, NULL); > > > -- Colin Percival Security Officer Emeritus, FreeBSD | The power to serve Founder, Tarsnap | www.tarsnap.com | Online backups for the truly paranoid
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