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/rtc/rtc-ps3.c | 73 +++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 73 insertions(+) create mode 100644 drivers/rtc/rtc-ps3.c (limited to 'drivers/rtc/rtc-ps3.c') diff --git a/drivers/rtc/rtc-ps3.c b/drivers/rtc/rtc-ps3.c new file mode 100644 index 000000000..6b098734c --- /dev/null +++ b/drivers/rtc/rtc-ps3.c @@ -0,0 +1,73 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * PS3 RTC Driver + * + * Copyright 2009 Sony Corporation + */ + +#include +#include +#include +#include + +#include +#include + + +static u64 read_rtc(void) +{ + int result; + u64 rtc_val; + u64 tb_val; + + result = lv1_get_rtc(&rtc_val, &tb_val); + BUG_ON(result); + + return rtc_val; +} + +static int ps3_get_time(struct device *dev, struct rtc_time *tm) +{ + rtc_time64_to_tm(read_rtc() + ps3_os_area_get_rtc_diff(), tm); + return 0; +} + +static int ps3_set_time(struct device *dev, struct rtc_time *tm) +{ + ps3_os_area_set_rtc_diff(rtc_tm_to_time64(tm) - read_rtc()); + return 0; +} + +static const struct rtc_class_ops ps3_rtc_ops = { + .read_time = ps3_get_time, + .set_time = ps3_set_time, +}; + +static int __init ps3_rtc_probe(struct platform_device *dev) +{ + struct rtc_device *rtc; + + rtc = devm_rtc_allocate_device(&dev->dev); + if (IS_ERR(rtc)) + return PTR_ERR(rtc); + + rtc->ops = &ps3_rtc_ops; + rtc->range_max = U64_MAX; + + platform_set_drvdata(dev, rtc); + + return devm_rtc_register_device(rtc); +} + +static struct platform_driver ps3_rtc_driver = { + .driver = { + .name = "rtc-ps3", + }, +}; + +module_platform_driver_probe(ps3_rtc_driver, ps3_rtc_probe); + +MODULE_AUTHOR("Sony Corporation"); +MODULE_LICENSE("GPL"); +MODULE_DESCRIPTION("ps3 RTC driver"); +MODULE_ALIAS("platform:rtc-ps3"); -- cgit v1.3.1