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/div.c | 80 ++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 80 insertions(+) create mode 100644 drivers/clk/sprd/div.c (limited to 'drivers/clk/sprd/div.c') diff --git a/drivers/clk/sprd/div.c b/drivers/clk/sprd/div.c new file mode 100644 index 000000000..cd57163a7 --- /dev/null +++ b/drivers/clk/sprd/div.c @@ -0,0 +1,80 @@ +// SPDX-License-Identifier: GPL-2.0 +// +// Spreadtrum divider clock driver +// +// Copyright (C) 2017 Spreadtrum, Inc. +// Author: Chunyan Zhang + +#include + +#include "div.h" + +static int sprd_div_determine_rate(struct clk_hw *hw, + struct clk_rate_request *req) +{ + struct sprd_div *cd = hw_to_sprd_div(hw); + + return divider_determine_rate(&cd->common.hw, req, NULL, cd->div.width, 0); +} + +unsigned long sprd_div_helper_recalc_rate(struct sprd_clk_common *common, + const struct sprd_div_internal *div, + unsigned long parent_rate) +{ + unsigned long val; + unsigned int reg; + + regmap_read(common->regmap, common->reg + div->offset, ®); + val = reg >> div->shift; + val &= (1 << div->width) - 1; + + return divider_recalc_rate(&common->hw, parent_rate, val, NULL, 0, + div->width); +} +EXPORT_SYMBOL_GPL(sprd_div_helper_recalc_rate); + +static unsigned long sprd_div_recalc_rate(struct clk_hw *hw, + unsigned long parent_rate) +{ + struct sprd_div *cd = hw_to_sprd_div(hw); + + return sprd_div_helper_recalc_rate(&cd->common, &cd->div, parent_rate); +} + +int sprd_div_helper_set_rate(const struct sprd_clk_common *common, + const struct sprd_div_internal *div, + unsigned long rate, + unsigned long parent_rate) +{ + unsigned long val; + unsigned int reg; + + val = divider_get_val(rate, parent_rate, NULL, + div->width, 0); + + regmap_read(common->regmap, common->reg + div->offset, ®); + reg &= ~GENMASK(div->width + div->shift - 1, div->shift); + + regmap_write(common->regmap, common->reg + div->offset, + reg | (val << div->shift)); + + return 0; + +} +EXPORT_SYMBOL_GPL(sprd_div_helper_set_rate); + +static int sprd_div_set_rate(struct clk_hw *hw, unsigned long rate, + unsigned long parent_rate) +{ + struct sprd_div *cd = hw_to_sprd_div(hw); + + return sprd_div_helper_set_rate(&cd->common, &cd->div, + rate, parent_rate); +} + +const struct clk_ops sprd_div_ops = { + .recalc_rate = sprd_div_recalc_rate, + .determine_rate = sprd_div_determine_rate, + .set_rate = sprd_div_set_rate, +}; +EXPORT_SYMBOL_GPL(sprd_div_ops); -- cgit v1.3.1