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| author | Sean Christopherson <seanjc@google.com> | 2026-09-23 09:37:21 -0700 |
|---|---|---|
| committer | Paolo Bonzini <pbonzini@redhat.com> | 2026-09-26 00:39:55 -0400 |
| commit | 93de2a6a4b91b72607136dd656edf03fb399d27f (patch) | |
| tree | 9220c76eb23cb39a146fac9692ee69afa4aa3135 /arch/microblaze/lib/mulsi3.S | |
| download | linux-stable-93de2a6a4b91b72607136dd656edf03fb399d27f.tar.gz linux-stable-93de2a6a4b91b72607136dd656edf03fb399d27f.zip | |
KVM: SEV: Do cache maintenance on the source VM during intra-host migrationgrafted
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 <fane@google.com>
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-ID: <20260923163721.1584779-3-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Diffstat (limited to 'arch/microblaze/lib/mulsi3.S')
| -rw-r--r-- | arch/microblaze/lib/mulsi3.S | 47 |
1 files changed, 47 insertions, 0 deletions
diff --git a/arch/microblaze/lib/mulsi3.S b/arch/microblaze/lib/mulsi3.S new file mode 100644 index 000000000..d6703a4d9 --- /dev/null +++ b/arch/microblaze/lib/mulsi3.S @@ -0,0 +1,47 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#include <linux/linkage.h> + +/* + * Multiply operation for 32 bit integers. + * Input : Operand1 in Reg r5 + * Operand2 in Reg r6 + * Output: Result [op1 * op2] in Reg r3 + */ + .text + .globl __mulsi3 + .type __mulsi3, @function + .ent __mulsi3 + +__mulsi3: + .frame r1, 0, r15 + add r3, r0, r0 + beqi r5, result_is_zero /* multiply by zero */ + beqi r6, result_is_zero /* multiply by zero */ + bgeid r5, r5_pos + xor r4, r5, r6 /* get the sign of the result */ + rsubi r5, r5, 0 /* make r5 positive */ +r5_pos: + bgei r6, r6_pos + rsubi r6, r6, 0 /* make r6 positive */ +r6_pos: + bri l1 +l2: + add r5, r5, r5 +l1: + srl r6, r6 + addc r7, r0, r0 + beqi r7, l2 + bneid r6, l2 + add r3, r3, r5 + blti r4, negateresult + rtsd r15, 8 + nop +negateresult: + rtsd r15, 8 + rsub r3, r3, r0 +result_is_zero: + rtsd r15, 8 + addi r3, r0, 0 + +.size __mulsi3, . - __mulsi3 +.end __mulsi3 |