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/clk/sprd/gate.c | 135 ++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 135 insertions(+) create mode 100644 drivers/clk/sprd/gate.c (limited to 'drivers/clk/sprd/gate.c') diff --git a/drivers/clk/sprd/gate.c b/drivers/clk/sprd/gate.c new file mode 100644 index 000000000..56e1714b5 --- /dev/null +++ b/drivers/clk/sprd/gate.c @@ -0,0 +1,135 @@ +// SPDX-License-Identifier: GPL-2.0 +// +// Spreadtrum gate clock driver +// +// Copyright (C) 2017 Spreadtrum, Inc. +// Author: Chunyan Zhang + +#include +#include + +#include "gate.h" + +static void clk_gate_toggle(const struct sprd_gate *sg, bool en) +{ + const struct sprd_clk_common *common = &sg->common; + unsigned int reg; + bool set = sg->flags & CLK_GATE_SET_TO_DISABLE ? true : false; + + set ^= en; + + regmap_read(common->regmap, common->reg, ®); + + if (set) + reg |= sg->enable_mask; + else + reg &= ~sg->enable_mask; + + regmap_write(common->regmap, common->reg, reg); +} + +static void clk_sc_gate_toggle(const struct sprd_gate *sg, bool en) +{ + const struct sprd_clk_common *common = &sg->common; + bool set = sg->flags & CLK_GATE_SET_TO_DISABLE ? 1 : 0; + unsigned int offset; + + set ^= en; + + /* + * Each set/clear gate clock has three registers: + * common->reg - base register + * common->reg + offset - set register + * common->reg + 2 * offset - clear register + */ + offset = set ? sg->sc_offset : sg->sc_offset * 2; + + regmap_write(common->regmap, common->reg + offset, + sg->enable_mask); +} + +static void sprd_gate_disable(struct clk_hw *hw) +{ + struct sprd_gate *sg = hw_to_sprd_gate(hw); + + clk_gate_toggle(sg, false); +} + +static int sprd_gate_enable(struct clk_hw *hw) +{ + struct sprd_gate *sg = hw_to_sprd_gate(hw); + + clk_gate_toggle(sg, true); + + return 0; +} + +static void sprd_sc_gate_disable(struct clk_hw *hw) +{ + struct sprd_gate *sg = hw_to_sprd_gate(hw); + + clk_sc_gate_toggle(sg, false); +} + +static int sprd_sc_gate_enable(struct clk_hw *hw) +{ + struct sprd_gate *sg = hw_to_sprd_gate(hw); + + clk_sc_gate_toggle(sg, true); + + return 0; +} + +static int sprd_pll_sc_gate_prepare(struct clk_hw *hw) +{ + struct sprd_gate *sg = hw_to_sprd_gate(hw); + + clk_sc_gate_toggle(sg, true); + udelay(sg->udelay); + + return 0; +} + +static int sprd_gate_is_enabled(struct clk_hw *hw) +{ + struct sprd_gate *sg = hw_to_sprd_gate(hw); + struct sprd_clk_common *common = &sg->common; + struct clk_hw *parent; + unsigned int reg; + + if (sg->flags & SPRD_GATE_NON_AON) { + parent = clk_hw_get_parent(hw); + if (!parent || !clk_hw_is_enabled(parent)) + return 0; + } + + regmap_read(common->regmap, common->reg, ®); + + if (sg->flags & CLK_GATE_SET_TO_DISABLE) + reg ^= sg->enable_mask; + + reg &= sg->enable_mask; + + return reg ? 1 : 0; +} + +const struct clk_ops sprd_gate_ops = { + .disable = sprd_gate_disable, + .enable = sprd_gate_enable, + .is_enabled = sprd_gate_is_enabled, +}; +EXPORT_SYMBOL_GPL(sprd_gate_ops); + +const struct clk_ops sprd_sc_gate_ops = { + .disable = sprd_sc_gate_disable, + .enable = sprd_sc_gate_enable, + .is_enabled = sprd_gate_is_enabled, +}; +EXPORT_SYMBOL_GPL(sprd_sc_gate_ops); + +const struct clk_ops sprd_pll_sc_gate_ops = { + .unprepare = sprd_sc_gate_disable, + .prepare = sprd_pll_sc_gate_prepare, + .is_enabled = sprd_gate_is_enabled, +}; +EXPORT_SYMBOL_GPL(sprd_pll_sc_gate_ops); -- cgit v1.3.1