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Groups > linux.kernel > #1248748
| From | Paolo Bonzini <pbonzini@redhat.com> |
|---|---|
| Newsgroups | linux.kernel |
| Subject | Re: [PATCH v3 0/5] KVM: nVMX: nested VPID emulation |
| Date | 2015-10-16 15:20 +0200 |
| Message-ID | <qkd5o-7oE-13@gated-at.bofh.it> (permalink) |
| References | <qjt2y-6rP-27@gated-at.bofh.it> <qkd5o-7oE-15@gated-at.bofh.it> |
| Organization | linux.* mail to news gateway |
On 16/10/2015 15:13, Wanpeng Li wrote: > Ping, :-) > On 10/14/15 12:12 AM, Wanpeng Li wrote: >> v2 -> v3: >> * separate nested_vmx_vpid_caps and move checks to patch 3/5, >> only rejoin them when reading the MSR. >> >> v1 -> v2: >> * set bit 32 of the VMX_EPT_VPID_CAP MSR >> * check against the supported types in the implementation of >> the INVVPID instruction >> * the memory operand must always be read even if it isn't needed >> (e.g., for type==global), similar to INVEPT >> * for single-context invalidation to check that VPID != 0, though in >> practice that doesn't matter because we don't want to support >> single-context invalidation >> * don't set msr's ept related bits if !enable_ept >> >> >> VPID is used to tag address space and avoid a TLB flush. Currently L0 use >> the same VPID to run L1 and all its guests. KVM flushes VPID when >> switching >> between L1 and L2. >> >> This patch advertises VPID to the L1 hypervisor, then address space of L1 >> and L2 can be separately treated and avoid TLB flush when swithing >> between >> L1 and L2. For each nested vmentry, if vpid12 is changed, reuse shadow >> vpid >> w/ an invvpid. >> >> Performance: >> >> run lmbench on L2 w/ 3.5 kernel. >> >> Context switching - times in microseconds - smaller is better >> ------------------------------------------------------------------------- >> Host OS 2p/0K 2p/16K 2p/64K 8p/16K 8p/64K 16p/16K >> 16p/64K >> ctxsw ctxsw ctxsw ctxsw ctxsw ctxsw >> ctxsw >> --------- ------------- ------ ------ ------ ------ ------ ------- >> ------- >> kernel Linux 3.5.0-1 1.2200 1.3700 1.4500 4.7800 2.3300 5.60000 >> 2.88000 nested VPID >> kernel Linux 3.5.0-1 1.2600 1.4300 1.5600 12.7 12.9 3.49000 >> 7.46000 vanilla >> >> Wanpeng Li (5): >> KVM: VMX: adjust interface to allocate/free_vpid >> KVM: VMX: introduce __vmx_flush_tlb to handle specific vpid >> KVM: nVMX: emulate the INVVPID instruction >> KVM: nVMX: nested VPID emulation >> KVM: nVMX: expose VPID capability to L1 >> >> arch/x86/include/asm/vmx.h | 1 + >> arch/x86/kvm/vmx.c | 151 >> ++++++++++++++++++++++++++++++++++++--------- >> 2 files changed, 123 insertions(+), 29 deletions(-) >> > Under test, will be committed to kvm/next soon. Paolo -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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[PATCH v3 0/5] KVM: nVMX: nested VPID emulation Wanpeng Li <wanpeng.li@hotmail.com> - 2015-10-14 14:10 +0200 Re: [PATCH v3 0/5] KVM: nVMX: nested VPID emulation Paolo Bonzini <pbonzini@redhat.com> - 2015-10-16 15:20 +0200 Re: [PATCH v3 0/5] KVM: nVMX: nested VPID emulation Wanpeng Li <wanpeng.li@hotmail.com> - 2015-10-16 15:20 +0200
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