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/net/phy/amd.c | 120 ++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 120 insertions(+) create mode 100644 drivers/net/phy/amd.c (limited to 'drivers/net/phy/amd.c') diff --git a/drivers/net/phy/amd.c b/drivers/net/phy/amd.c new file mode 100644 index 000000000..75b5fe655 --- /dev/null +++ b/drivers/net/phy/amd.c @@ -0,0 +1,120 @@ +// SPDX-License-Identifier: GPL-2.0+ +/* + * Driver for AMD am79c PHYs + * + * Author: Heiko Schocher + * + * Copyright (c) 2011 DENX Software Engineering GmbH + */ +#include +#include +#include +#include +#include +#include + +#define PHY_ID_AC101L 0x00225520 +#define PHY_ID_AM79C874 0x0022561b + +#define MII_AM79C_IR 17 /* Interrupt Status/Control Register */ +#define MII_AM79C_IR_EN_LINK 0x0400 /* IR enable Linkstate */ +#define MII_AM79C_IR_EN_ANEG 0x0100 /* IR enable Aneg Complete */ +#define MII_AM79C_IR_IMASK_INIT (MII_AM79C_IR_EN_LINK | MII_AM79C_IR_EN_ANEG) + +#define MII_AM79C_IR_LINK_DOWN BIT(2) +#define MII_AM79C_IR_ANEG_DONE BIT(0) +#define MII_AM79C_IR_IMASK_STAT (MII_AM79C_IR_LINK_DOWN | MII_AM79C_IR_ANEG_DONE) + +MODULE_DESCRIPTION("AMD PHY driver"); +MODULE_AUTHOR("Heiko Schocher "); +MODULE_LICENSE("GPL"); + +static int am79c_ack_interrupt(struct phy_device *phydev) +{ + int err; + + err = phy_read(phydev, MII_BMSR); + if (err < 0) + return err; + + err = phy_read(phydev, MII_AM79C_IR); + if (err < 0) + return err; + + return 0; +} + +static int am79c_config_init(struct phy_device *phydev) +{ + return 0; +} + +static int am79c_config_intr(struct phy_device *phydev) +{ + int err; + + if (phydev->interrupts == PHY_INTERRUPT_ENABLED) { + err = am79c_ack_interrupt(phydev); + if (err) + return err; + + err = phy_write(phydev, MII_AM79C_IR, MII_AM79C_IR_IMASK_INIT); + } else { + err = phy_write(phydev, MII_AM79C_IR, 0); + if (err) + return err; + + err = am79c_ack_interrupt(phydev); + } + + return err; +} + +static irqreturn_t am79c_handle_interrupt(struct phy_device *phydev) +{ + int irq_status; + + irq_status = phy_read(phydev, MII_AM79C_IR); + if (irq_status < 0) { + phy_error(phydev); + return IRQ_NONE; + } + + if (!(irq_status & MII_AM79C_IR_IMASK_STAT)) + return IRQ_NONE; + + phy_trigger_machine(phydev); + + return IRQ_HANDLED; +} + +static struct phy_driver am79c_drivers[] = { + { + .phy_id = PHY_ID_AM79C874, + .name = "AM79C874", + .phy_id_mask = 0xfffffff0, + /* PHY_BASIC_FEATURES */ + .config_init = am79c_config_init, + .config_intr = am79c_config_intr, + .handle_interrupt = am79c_handle_interrupt, + }, + { + .phy_id = PHY_ID_AC101L, + .name = "AC101L", + .phy_id_mask = 0xfffffff0, + /* PHY_BASIC_FEATURES */ + .config_init = am79c_config_init, + .config_intr = am79c_config_intr, + .handle_interrupt = am79c_handle_interrupt, + }, +}; + +module_phy_driver(am79c_drivers); + +static const struct mdio_device_id __maybe_unused amd_tbl[] = { + { PHY_ID_AC101L, 0xfffffff0 }, + { PHY_ID_AM79C874, 0xfffffff0 }, + { } +}; + +MODULE_DEVICE_TABLE(mdio, amd_tbl); -- cgit v1.3.1