From 93de2a6a4b91b72607136dd656edf03fb399d27f Mon Sep 17 00:00:00 2001 From: Sean Christopherson Date: Wed, 23 Sep 2026 09:37:21 -0700 Subject: KVM: SEV: Do cache maintenance on the source VM during intra-host migration Manually perform cache maintenance on the source VM during intra-host migration to ensure no stale data is left in CPU caches after the VM is destroyed. Because the source VM is "converted" to a non-SEV VM, KVM's memory reclaim flows won't trigger cache maintenance, e.g. when all guest memory is reclaimed in response to detaching from the mmu_notifier. Note, relying on the destination VM to do cache maintenance isn't an option as KVM doesn't require identical guest memory configurations, i.e. the source VM may have access to memory that the destination VM does not. Enforcing equivalent memory configurations is infeasible, as it would require a *deep* comparison of memslots, e.g. to verify that not only are the memslot identical, but what the memslots point at is also identical. Fixes: b56639318bb2 ("KVM: SEV: Add support for SEV intra host migration") Cc: stable@vger.kernel.org Reported-by: Stefan Teodorescu Signed-off-by: Sean Christopherson Message-ID: <20260923163721.1584779-3-seanjc@google.com> Signed-off-by: Paolo Bonzini --- drivers/macintosh/macio_sysfs.c | 82 +++++++++++++++++++++++++++++++++++++++++ 1 file changed, 82 insertions(+) create mode 100644 drivers/macintosh/macio_sysfs.c (limited to 'drivers/macintosh/macio_sysfs.c') diff --git a/drivers/macintosh/macio_sysfs.c b/drivers/macintosh/macio_sysfs.c new file mode 100644 index 000000000..2bbe359b2 --- /dev/null +++ b/drivers/macintosh/macio_sysfs.c @@ -0,0 +1,82 @@ +// SPDX-License-Identifier: GPL-2.0 +#include +#include +#include +#include +#include + +static ssize_t +compatible_show (struct device *dev, struct device_attribute *attr, char *buf) +{ + struct platform_device *of; + const char *compat; + int cplen; + int length = 0; + + of = &to_macio_device (dev)->ofdev; + compat = of_get_property(of->dev.of_node, "compatible", &cplen); + if (!compat) { + *buf = '\0'; + return 0; + } + while (cplen > 0) { + int l; + length += sprintf (buf, "%s\n", compat); + buf += length; + l = strlen (compat) + 1; + compat += l; + cplen -= l; + } + + return length; +} +static DEVICE_ATTR_RO(compatible); + +static ssize_t modalias_show (struct device *dev, struct device_attribute *attr, + char *buf) +{ + return of_device_modalias(dev, buf, PAGE_SIZE); +} + +static ssize_t devspec_show(struct device *dev, + struct device_attribute *attr, char *buf) +{ + struct platform_device *ofdev; + + ofdev = to_platform_device(dev); + return sprintf(buf, "%pOF\n", ofdev->dev.of_node); +} +static DEVICE_ATTR_RO(modalias); +static DEVICE_ATTR_RO(devspec); + +static ssize_t name_show(struct device *dev, + struct device_attribute *attr, char *buf) +{ + return sprintf(buf, "%pOFn\n", dev->of_node); +} +static DEVICE_ATTR_RO(name); + +static ssize_t type_show(struct device *dev, + struct device_attribute *attr, char *buf) +{ + return sprintf(buf, "%s\n", of_node_get_device_type(dev->of_node)); +} +static DEVICE_ATTR_RO(type); + +static struct attribute *macio_dev_attrs[] = { + &dev_attr_name.attr, + &dev_attr_type.attr, + &dev_attr_compatible.attr, + &dev_attr_modalias.attr, + &dev_attr_devspec.attr, + NULL, +}; + +static const struct attribute_group macio_dev_group = { + .attrs = macio_dev_attrs, +}; + +const struct attribute_group *macio_dev_groups[] = { + &macio_dev_group, + NULL, +}; -- cgit v1.3.1