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 --- arch/alpha/Kconfig.debug | 38 ++++++++++++++++++++++++++++++++++++++ 1 file changed, 38 insertions(+) create mode 100644 arch/alpha/Kconfig.debug (limited to 'arch/alpha/Kconfig.debug') diff --git a/arch/alpha/Kconfig.debug b/arch/alpha/Kconfig.debug new file mode 100644 index 000000000..f85f4281c --- /dev/null +++ b/arch/alpha/Kconfig.debug @@ -0,0 +1,38 @@ +# SPDX-License-Identifier: GPL-2.0 + +config EARLY_PRINTK + bool + depends on ALPHA_GENERIC || ALPHA_SRM + default y + +config ALPHA_LEGACY_START_ADDRESS + bool "Legacy kernel start address" + depends on ALPHA_GENERIC + default n + help + The 2.4 kernel changed the kernel start address from 0x310000 + to 0x810000 to make room for the Wildfire's larger SRM console. + Recent consoles on Titan and Marvel machines also require the + extra room. + + If you're using aboot 0.7 or later, the bootloader will examine the + ELF headers to determine where to transfer control. Unfortunately, + most older bootloaders -- APB or MILO -- hardcoded the kernel start + address rather than examining the ELF headers, and the result is a + hard lockup. + + Say Y if you have a broken bootloader. Say N if you do not, or if + you wish to run on Wildfire, Titan, or Marvel. + +config ALPHA_LEGACY_START_ADDRESS + bool + depends on !ALPHA_GENERIC && !ALPHA_TITAN && !ALPHA_MARVEL && !ALPHA_WILDFIRE + default y + +config MATHEMU + tristate "Kernel FP software completion" if DEBUG_KERNEL && !SMP + default y if !DEBUG_KERNEL || SMP + help + This option is required for IEEE compliant floating point arithmetic + on the Alpha. The only time you would ever not say Y is to say M in + order to debug the code. Say Y unless you know what you are doing. -- cgit v1.3.1