Revision 3d7746bea92530e8695258a3cf3ddec7a135edd6 authored by David Woodhouse on 06 January 2021, 15:39:58 UTC, committed by Juergen Gross on 13 January 2021, 15:12:09 UTC
Only the IPI-related functions in the smp_ops should be conditional on the vector callback being available. The rest should still happen: • xen_hvm_smp_prepare_boot_cpu() This function does two things, both of which should still happen if there is no vector callback support. The call to xen_vcpu_setup() for vCPU0 should still happen as it just sets up the vcpu_info for CPU0. That does happen for the secondary vCPUs too, from xen_cpu_up_prepare_hvm(). The second thing it does is call xen_init_spinlocks(), which perhaps counter-intuitively should *also* still be happening in the case without vector callbacks, so that it can clear its local xen_pvspin flag and disable the virt_spin_lock_key accordingly. Checking xen_have_vector_callback in xen_init_spinlocks() itself would affect PV guests, so set the global nopvspin flag in xen_hvm_smp_init() instead, when vector callbacks aren't available. • xen_hvm_smp_prepare_cpus() This does some IPI-related setup by calling xen_smp_intr_init() and xen_init_lock_cpu(), which can be made conditional. And it sets the xen_vcpu_id to XEN_VCPU_ID_INVALID for all possible CPUS, which does need to happen. • xen_smp_cpus_done() This offlines any vCPUs which doesn't fit in the global shared_info page, if separate vcpu_info placement isn't available. That part also needs to happen regardless of vector callback support. • xen_hvm_cpu_die() This doesn't actually do anything other than commin_cpu_die() right right now in the !vector_callback case; all three teardown functions it calls should be no-ops. But to guard against future regressions it's useful to call it anyway, and for it to explicitly check for xen_have_vector_callback before calling those additional functions. Signed-off-by: David Woodhouse <dwmw@amazon.co.uk> Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> Link: https://lore.kernel.org/r/20210106153958.584169-6-dwmw2@infradead.org Signed-off-by: Juergen Gross <jgross@suse.com>
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pgalloc-track.h
/* SPDX-License-Identifier: GPL-2.0 */
#ifndef _LINUX_PGALLLC_TRACK_H
#define _LINUX_PGALLLC_TRACK_H
#if defined(CONFIG_MMU)
static inline p4d_t *p4d_alloc_track(struct mm_struct *mm, pgd_t *pgd,
unsigned long address,
pgtbl_mod_mask *mod_mask)
{
if (unlikely(pgd_none(*pgd))) {
if (__p4d_alloc(mm, pgd, address))
return NULL;
*mod_mask |= PGTBL_PGD_MODIFIED;
}
return p4d_offset(pgd, address);
}
static inline pud_t *pud_alloc_track(struct mm_struct *mm, p4d_t *p4d,
unsigned long address,
pgtbl_mod_mask *mod_mask)
{
if (unlikely(p4d_none(*p4d))) {
if (__pud_alloc(mm, p4d, address))
return NULL;
*mod_mask |= PGTBL_P4D_MODIFIED;
}
return pud_offset(p4d, address);
}
static inline pmd_t *pmd_alloc_track(struct mm_struct *mm, pud_t *pud,
unsigned long address,
pgtbl_mod_mask *mod_mask)
{
if (unlikely(pud_none(*pud))) {
if (__pmd_alloc(mm, pud, address))
return NULL;
*mod_mask |= PGTBL_PUD_MODIFIED;
}
return pmd_offset(pud, address);
}
#endif /* CONFIG_MMU */
#define pte_alloc_kernel_track(pmd, address, mask) \
((unlikely(pmd_none(*(pmd))) && \
(__pte_alloc_kernel(pmd) || ({*(mask)|=PGTBL_PMD_MODIFIED;0;})))?\
NULL: pte_offset_kernel(pmd, address))
#endif /* _LINUX_PGALLLC_TRACK_H */
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