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Revision 32ffa4f71e10009498ae6b54da65ab316db967bd authored by Axel Rasmussen on 19 May 2021, 20:03:33 UTC, committed by Paolo Bonzini on 27 May 2021, 11:45:55 UTC 
KVM: selftests: compute correct demand paging size
 
This is a preparatory commit needed before we can use different kinds of
backing pages for guest memory.

Previously, we used perf_test_args.host_page_size, which is the host's
native page size (commonly 4K). For VM_MEM_SRC_ANONYMOUS this turns out
to be okay, but in a follow-up commit we want to allow using different
kinds of backing memory.

Take VM_MEM_SRC_ANONYMOUS_HUGETLB for example. Without this change, if
we used that backing page type, when we issued a UFFDIO_COPY ioctl we'd
only do so with 4K, rather than the full 2M of a backing hugepage. In
this case, UFFDIO_COPY returns -EINVAL (__mcopy_atomic_hugetlb checks
the size).

Signed-off-by: Axel Rasmussen <axelrasmussen@google.com>
Message-Id: <20210519200339.829146-5-axelrasmussen@google.com>
Reviewed-by: Ben Gardon <bgardon@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
1 parent 25408e5
Raw File
dbgp.c 
// SPDX-License-Identifier: GPL-2.0-only
#include <linux/pci.h>
#include <linux/usb.h>
#include <linux/usb/ehci_def.h>
#include <linux/usb/hcd.h>
#include <asm/xen/hypercall.h>
#include <xen/interface/physdev.h>
#include <xen/xen.h>

static int xen_dbgp_op(struct usb_hcd *hcd, int op)
{
#ifdef CONFIG_PCI
	const struct device *ctrlr = hcd_to_bus(hcd)->controller;
#endif
	struct physdev_dbgp_op dbgp;

	if (!xen_initial_domain())
		return 0;

	dbgp.op = op;

#ifdef CONFIG_PCI
	if (dev_is_pci(ctrlr)) {
		const struct pci_dev *pdev = to_pci_dev(ctrlr);

		dbgp.u.pci.seg = pci_domain_nr(pdev->bus);
		dbgp.u.pci.bus = pdev->bus->number;
		dbgp.u.pci.devfn = pdev->devfn;
		dbgp.bus = PHYSDEVOP_DBGP_BUS_PCI;
	} else
#endif
		dbgp.bus = PHYSDEVOP_DBGP_BUS_UNKNOWN;

	return HYPERVISOR_physdev_op(PHYSDEVOP_dbgp_op, &dbgp);
}

int xen_dbgp_reset_prep(struct usb_hcd *hcd)
{
	return xen_dbgp_op(hcd, PHYSDEVOP_DBGP_RESET_PREPARE);
}

int xen_dbgp_external_startup(struct usb_hcd *hcd)
{
	return xen_dbgp_op(hcd, PHYSDEVOP_DBGP_RESET_DONE);
}

#ifndef CONFIG_EARLY_PRINTK_DBGP
#include <linux/export.h>
EXPORT_SYMBOL_GPL(xen_dbgp_reset_prep);
EXPORT_SYMBOL_GPL(xen_dbgp_external_startup);
#endif
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