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/gpio/gpiolib-shared.h | 51 +++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 51 insertions(+) create mode 100644 drivers/gpio/gpiolib-shared.h (limited to 'drivers/gpio/gpiolib-shared.h') diff --git a/drivers/gpio/gpiolib-shared.h b/drivers/gpio/gpiolib-shared.h new file mode 100644 index 000000000..618756f6c --- /dev/null +++ b/drivers/gpio/gpiolib-shared.h @@ -0,0 +1,51 @@ +/* SPDX-License-Identifier: GPL-2.0 */ + +#ifndef __LINUX_GPIO_SHARED_H +#define __LINUX_GPIO_SHARED_H + +#include + +struct gpio_device; +struct gpio_desc; +struct device; +struct fwnode_handle; + +#if IS_ENABLED(CONFIG_GPIO_SHARED) + +int gpiochip_setup_shared(struct gpio_chip *gc); +void gpio_device_teardown_shared(struct gpio_device *gdev); +int gpio_shared_add_proxy_lookup(struct device *consumer, + struct fwnode_handle *fwnode, + const char *con_id, unsigned long lflags); + +#else + +static inline int gpiochip_setup_shared(struct gpio_chip *gc) +{ + return 0; +} + +static inline void gpio_device_teardown_shared(struct gpio_device *gdev) { } + +static inline int gpio_shared_add_proxy_lookup(struct device *consumer, + struct fwnode_handle *fwnode, + const char *con_id, + unsigned long lflags) +{ + return 0; +} + +#endif /* CONFIG_GPIO_SHARED */ + +struct gpio_shared_desc { + struct gpio_desc *desc; + unsigned long cfg; + unsigned int usecnt; + unsigned int votecnt; + int def_val; + struct mutex mutex; /* serializes all proxy operations on this descriptor */ +}; + +struct gpio_shared_desc *devm_gpiod_shared_get(struct device *dev); + +#endif /* __LINUX_GPIO_SHARED_H */ -- cgit v1.3.1