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| author | Neel Natu <neel@FreeBSD.org> | 2014-09-13 22:16:40 +0000 |
|---|---|---|
| committer | Neel Natu <neel@FreeBSD.org> | 2014-09-13 22:16:40 +0000 |
| commit | c2a875f97078392b2f0364d4f284dfdfc2389377 (patch) | |
| tree | 70a00007f69968f48c3915bfacf511d0235b5081 /sys/amd64/vmm/vmm_instruction_emul.c | |
| parent | 442a04ca833b3ace4813c496e5f458f5c4795e71 (diff) | |
| download | src-c2a875f97078392b2f0364d4f284dfdfc2389377.tar.gz src-c2a875f97078392b2f0364d4f284dfdfc2389377.zip | |
AMD processors that have the SVM decode assist capability will store the
instruction bytes in the VMCB on a nested page fault. This is useful because
it saves having to walk the guest page tables to fetch the instruction.
vie_init() now takes two additional parameters 'inst_bytes' and 'inst_len'
that map directly to 'vie->inst[]' and 'vie->num_valid'.
The instruction emulation handler skips calling 'vmm_fetch_instruction()'
if 'vie->num_valid' is non-zero.
The use of this capability can be turned off by setting the sysctl/tunable
'hw.vmm.svm.disable_npf_assist' to '1'.
Reviewed by: Anish Gupta (akgupt3@gmail.com)
Discussed with: grehan
Notes
Notes:
svn path=/projects/bhyve_svm/; revision=271554
Diffstat (limited to 'sys/amd64/vmm/vmm_instruction_emul.c')
| -rw-r--r-- | sys/amd64/vmm/vmm_instruction_emul.c | 9 |
1 files changed, 8 insertions, 1 deletions
diff --git a/sys/amd64/vmm/vmm_instruction_emul.c b/sys/amd64/vmm/vmm_instruction_emul.c index 185b198f658d..60e7a572ae7d 100644 --- a/sys/amd64/vmm/vmm_instruction_emul.c +++ b/sys/amd64/vmm/vmm_instruction_emul.c @@ -1025,13 +1025,20 @@ vie_calculate_gla(enum vm_cpu_mode cpu_mode, enum vm_reg_name seg, #ifdef _KERNEL void -vie_init(struct vie *vie) +vie_init(struct vie *vie, const char *inst_bytes, int inst_length) { + KASSERT(inst_length >= 0 && inst_length <= VIE_INST_SIZE, + ("%s: invalid instruction length (%d)", __func__, inst_length)); bzero(vie, sizeof(struct vie)); vie->base_register = VM_REG_LAST; vie->index_register = VM_REG_LAST; + + if (inst_length) { + bcopy(inst_bytes, vie->inst, inst_length); + vie->num_valid = inst_length; + } } static int |