KVM: SEV: Do cache maintenance on the source VM during intra-host migrationgrafted

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 <fane@google.com>
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-ID: <20260923163721.1584779-3-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

1 files changed, 107 insertions, 0 deletions

diff --git a/drivers/phy/samsung/Kconfig b/drivers/phy/samsung/Kconfig
new file mode 100644
index 000000000..b7ab40290
--- /dev/null
+++ b/drivers/phy/samsung/Kconfig
@@ -0,0 +1,107 @@
+# SPDX-License-Identifier: GPL-2.0-only
+#
+# Phy drivers for Samsung platforms
+#
+config PHY_EXYNOS_DP_VIDEO
+	tristate "Exynos SoC series Display Port PHY driver"
+	depends on OF
+	depends on ARCH_EXYNOS || COMPILE_TEST
+	default ARCH_EXYNOS
+	select GENERIC_PHY
+	help
+	  Support for Display Port PHY found on Samsung Exynos SoCs.
+
+config PHY_EXYNOS_MIPI_VIDEO
+	tristate "S5P/Exynos SoC series MIPI CSI-2/DSI PHY driver"
+	depends on HAS_IOMEM
+	depends on ARCH_S5PV210 || ARCH_EXYNOS || COMPILE_TEST
+	select GENERIC_PHY
+	default y if ARCH_S5PV210 || ARCH_EXYNOS
+	help
+	  Support for MIPI CSI-2 and MIPI DSI DPHY found on Samsung S5P
+	  and Exynos SoCs.
+
+config PHY_EXYNOS_PCIE
+	bool "Exynos PCIe PHY driver"
+	depends on OF && (ARCH_EXYNOS || COMPILE_TEST)
+	select GENERIC_PHY
+	help
+	  Enable PCIe PHY support for Exynos SoC series.
+	  This driver provides PHY interface for Exynos PCIe controller.
+
+config PHY_SAMSUNG_UFS
+	tristate "Exynos SoC series UFS PHY driver"
+	depends on OF && (ARCH_EXYNOS || COMPILE_TEST)
+	select GENERIC_PHY
+	select MFD_SYSCON
+	help
+	  Enable this to support the Samsung Exynos SoC UFS PHY driver for
+	  Samsung Exynos SoCs. This driver provides the interface for UFS host
+	  controller to do PHY related programming.
+
+config PHY_SAMSUNG_USB2
+	tristate "S5P/Exynos SoC series USB 2.0 PHY driver"
+	depends on HAS_IOMEM
+	depends on USB_EHCI_EXYNOS || USB_OHCI_EXYNOS || USB_DWC2 || COMPILE_TEST
+	select GENERIC_PHY
+	select MFD_SYSCON
+	default ARCH_EXYNOS
+	help
+	  Enable this to support the Samsung USB 2.0 PHY driver for Samsung
+	  S5Pv210 and Exynos SoCs. This driver provides the interface for USB
+	  2.0 PHY. Support for particular PHYs will be enabled based on the SoC
+	  type in addition to this driver.
+
+config PHY_EXYNOS4210_USB2
+	bool
+	depends on PHY_SAMSUNG_USB2
+	default CPU_EXYNOS4210
+
+config PHY_EXYNOS4X12_USB2
+	bool
+	depends on PHY_SAMSUNG_USB2
+	default SOC_EXYNOS3250 || SOC_EXYNOS4212 || SOC_EXYNOS4412
+
+config PHY_EXYNOS5250_USB2
+	bool
+	depends on PHY_SAMSUNG_USB2
+	default SOC_EXYNOS5250 || SOC_EXYNOS5420
+
+config PHY_S5PV210_USB2
+	bool "Support for S5PV210"
+	depends on PHY_SAMSUNG_USB2
+	depends on ARCH_S5PV210 || COMPILE_TEST
+	help
+	  Enable USB PHY support for S5PV210. This option requires that Samsung
+	  USB 2.0 PHY driver is enabled and means that support for this
+	  particular SoC is compiled in the driver. In case of S5PV210 two phys
+	  are available - device and host.
+
+config PHY_EXYNOS5_USBDRD
+	tristate "Exynos5 SoC series USB DRD PHY driver"
+	depends on (ARCH_EXYNOS && OF) || COMPILE_TEST
+	depends on HAS_IOMEM
+	depends on TYPEC || !TYPEC
+	depends on USB_DWC3_EXYNOS
+	select GENERIC_PHY
+	select MFD_SYSCON
+	default ARCH_EXYNOS
+	help
+	  Enable USB DRD PHY support for Exynos 5 SoC series.
+	  This driver provides PHY interface for USB 3.0 DRD controller
+	  present on Exynos5 SoC series.
+
+config PHY_EXYNOS5250_SATA
+	tristate "Exynos5250 Sata SerDes/PHY driver"
+	depends on SOC_EXYNOS5250
+	depends on HAS_IOMEM
+	depends on OF
+	select GENERIC_PHY
+	select I2C
+	select I2C_S3C2410
+	select MFD_SYSCON
+	help
+	  Enable this to support SATA SerDes/Phy found on Samsung's
+	  Exynos5250 based SoCs.This SerDes/Phy supports SATA 1.5 Gb/s,
+	  SATA 3.0 Gb/s, SATA 6.0 Gb/s speeds. It supports one SATA host
+	  port to accept one SATA device.