[PATCH v2 11/12] x86/sev: Handle CLFLUSH MMIO events
From: Joerg Roedel <joro@8bytes.org>
Date: 2021-09-13 15:56:38
Also in:
kvm, lkml, virtualization
Subsystem:
the rest, x86 architecture (32-bit and 64-bit) · Maintainers:
Linus Torvalds, Thomas Gleixner, Ingo Molnar, Borislav Petkov, Dave Hansen
From: Joerg Roedel <redacted> Handle CLFLUSH instruction to MMIO memory in the #VC handler. The instruction is ignored by the handler, as the Hypervisor is responsible for cache management of emulated MMIO memory. Signed-off-by: Joerg Roedel <redacted> --- arch/x86/kernel/sev-shared.c | 9 +++++++++ 1 file changed, 9 insertions(+)
diff --git a/arch/x86/kernel/sev-shared.c b/arch/x86/kernel/sev-shared.c
index a7a0793c4f98..682fa202444f 100644
--- a/arch/x86/kernel/sev-shared.c
+++ b/arch/x86/kernel/sev-shared.c@@ -632,6 +632,15 @@ static enum es_result vc_handle_mmio_twobyte_ops(struct ghcb *ghcb, long *reg_data; switch (insn->opcode.bytes[1]) { + /* CLFLUSH */ + case 0xae: + /* + * Ignore CLFLUSHes - those go to emulated MMIO anyway and the + * hypervisor is responsible for cache management. + */ + ret = ES_OK; + break; + /* MMIO Read w/ zero-extension */ case 0xb6: bytes = 1;
--
2.33.0