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/char/tpm/tpm-dev.h | 33 +++++++++++++++++++++++++++++++++ 1 file changed, 33 insertions(+) create mode 100644 drivers/char/tpm/tpm-dev.h (limited to 'drivers/char/tpm/tpm-dev.h') diff --git a/drivers/char/tpm/tpm-dev.h b/drivers/char/tpm/tpm-dev.h new file mode 100644 index 000000000..f3742bcc7 --- /dev/null +++ b/drivers/char/tpm/tpm-dev.h @@ -0,0 +1,33 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef _TPM_DEV_H +#define _TPM_DEV_H + +#include +#include "tpm.h" + +struct file_priv { + struct tpm_chip *chip; + struct tpm_space *space; + + struct mutex buffer_mutex; + struct timer_list user_read_timer; /* user needs to claim result */ + struct work_struct timeout_work; + struct work_struct async_work; + wait_queue_head_t async_wait; + ssize_t response_length; + bool response_read; + bool command_enqueued; + + u8 data_buffer[TPM_BUFSIZE]; +}; + +void tpm_common_open(struct file *file, struct tpm_chip *chip, + struct file_priv *priv, struct tpm_space *space); +ssize_t tpm_common_read(struct file *file, char __user *buf, + size_t size, loff_t *off); +ssize_t tpm_common_write(struct file *file, const char __user *buf, + size_t size, loff_t *off); +__poll_t tpm_common_poll(struct file *file, poll_table *wait); + +void tpm_common_release(struct file *file, struct file_priv *priv); +#endif -- cgit v1.3.1