[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] [Xen-changelog] [xen master] x86/HVM: don't retain emulated insn cache when exiting back to guest
commit 5fcb26e69e8089e20c9168774bee681b8f5a3187 Author: Jan Beulich <jbeulich@xxxxxxxx> AuthorDate: Wed Dec 6 12:50:23 2017 +0100 Commit: Jan Beulich <jbeulich@xxxxxxxx> CommitDate: Wed Dec 6 12:50:23 2017 +0100 x86/HVM: don't retain emulated insn cache when exiting back to guest vio->mmio_retry is being set when a repeated string insn is being split up. In that case we'll exit to the guest, expecting immediate re-entry. Interruptions, however, may be serviced by the guest before re-entry from the repeated string insn. Any emulation needed in the course of handling the interruption must not fetch from the internally maintained cache. Signed-off-by: Jan Beulich <jbeulich@xxxxxxxx> Reviewed-by: Paul Durrant <paul.durrant@xxxxxxxxxx> --- xen/arch/x86/hvm/emulate.c | 18 ++++++++++-------- 1 file changed, 10 insertions(+), 8 deletions(-) diff --git a/xen/arch/x86/hvm/emulate.c b/xen/arch/x86/hvm/emulate.c index b8c94c9..c9fae88 100644 --- a/xen/arch/x86/hvm/emulate.c +++ b/xen/arch/x86/hvm/emulate.c @@ -2110,20 +2110,22 @@ static int _hvm_emulate_one(struct hvm_emulate_ctxt *hvmemul_ctxt, vio->mmio_retry = 0; - rc = x86_emulate(&hvmemul_ctxt->ctxt, ops); - - if ( rc == X86EMUL_OKAY && vio->mmio_retry ) - rc = X86EMUL_RETRY; - if ( rc != X86EMUL_RETRY ) + switch ( rc = x86_emulate(&hvmemul_ctxt->ctxt, ops) ) { + case X86EMUL_OKAY: + if ( vio->mmio_retry ) + rc = X86EMUL_RETRY; + /* fall through */ + default: vio->mmio_cache_count = 0; vio->mmio_insn_bytes = 0; - } - else - { + break; + + case X86EMUL_RETRY: BUILD_BUG_ON(sizeof(vio->mmio_insn) < sizeof(hvmemul_ctxt->insn_buf)); vio->mmio_insn_bytes = hvmemul_ctxt->insn_buf_bytes; memcpy(vio->mmio_insn, hvmemul_ctxt->insn_buf, vio->mmio_insn_bytes); + break; } if ( hvmemul_ctxt->ctxt.retire.singlestep ) -- generated by git-patchbot for /home/xen/git/xen.git#master _______________________________________________ Xen-changelog mailing list Xen-changelog@xxxxxxxxxxxxxxxxxxxx https://lists.xenproject.org/xen-changelog
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