From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-17.3 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, USER_AGENT_SANE_1 autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id D8080C433ED for ; Tue, 13 Apr 2021 21:08:28 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id A5F9D61244 for ; Tue, 13 Apr 2021 21:08:28 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1346618AbhDMVIr (ORCPT ); Tue, 13 Apr 2021 17:08:47 -0400 Received: from smtp-fw-33001.amazon.com ([207.171.190.10]:56992 "EHLO smtp-fw-33001.amazon.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1344575AbhDMVIq (ORCPT ); Tue, 13 Apr 2021 17:08:46 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=amazon.de; i=@amazon.de; q=dns/txt; s=amazon201209; t=1618348106; x=1649884106; h=date:from:to:cc:message-id:references:mime-version: in-reply-to:subject; bh=oXscWfXptDs7/ZJws9fZMwjKGAhwqVVLijAjsYycvy4=; b=Ret1hHFI49xuJ0yhp3a+0xPZfaP2M9CETQmC9dNPqItgPCVXVe8APaLw IroTGE7tphWiNFpeId9dAhImxcIK+aq3DLEDydAiCkO62Lf1qVnNF91+E 8S/O22z6d4FSP8w7p1MlnNZ3Io8HoGLKG/uOZ4VwHprPP7anZPxRtKXHS g=; X-IronPort-AV: E=Sophos;i="5.82,220,1613433600"; d="scan'208";a="118195962" Subject: Re: [PATCH v2 3/4] KVM: x86: kvm_hv_flush_tlb use inputs from XMM registers Received: from pdx4-co-svc-p1-lb2-vlan2.amazon.com (HELO email-inbound-relay-1e-c7f73527.us-east-1.amazon.com) ([10.25.36.210]) by smtp-border-fw-out-33001.sea14.amazon.com with ESMTP; 13 Apr 2021 21:08:18 +0000 Received: from EX13D28EUC003.ant.amazon.com (iad12-ws-svc-p26-lb9-vlan3.iad.amazon.com [10.40.163.38]) by email-inbound-relay-1e-c7f73527.us-east-1.amazon.com (Postfix) with ESMTPS id 45C3FBD5C2; Tue, 13 Apr 2021 21:08:11 +0000 (UTC) Received: from uc8bbc9586ea454.ant.amazon.com (10.43.161.39) by EX13D28EUC003.ant.amazon.com (10.43.164.43) with Microsoft SMTP Server (TLS) id 15.0.1497.2; Tue, 13 Apr 2021 21:08:03 +0000 Date: Tue, 13 Apr 2021 23:07:59 +0200 From: Siddharth Chandrasekaran To: Vitaly Kuznetsov CC: Alexander Graf , Evgeny Iakovlev , Liran Alon , Ioannis Aslanidis , , , , "K. Y. Srinivasan" , Haiyang Zhang , Stephen Hemminger , Wei Liu , Thomas Gleixner , Ingo Molnar , Borislav Petkov , , "H. Peter Anvin" , Paolo Bonzini , "Sean Christopherson" , Wanpeng Li , "Jim Mattson" , Joerg Roedel Message-ID: <20210413210758.GA10240@uc8bbc9586ea454.ant.amazon.com> References: <87sg3u5l8z.fsf@vitty.brq.redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Disposition: inline In-Reply-To: <87sg3u5l8z.fsf@vitty.brq.redhat.com> User-Agent: Mutt/1.9.4 (2018-02-28) X-Originating-IP: [10.43.161.39] X-ClientProxiedBy: EX13D20UWA003.ant.amazon.com (10.43.160.97) To EX13D28EUC003.ant.amazon.com (10.43.164.43) Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org On Tue, Apr 13, 2021 at 04:09:48PM +0200, Vitaly Kuznetsov wrote: > Siddharth Chandrasekaran writes: > > Hyper-V supports the use of XMM registers to perform fast hypercalls. > > This allows guests to take advantage of the improved performance of the > > fast hypercall interface even though a hypercall may require more than > > (the current maximum of) two input registers. > > > > The XMM fast hypercall interface uses six additional XMM registers (XMM0 > > to XMM5) to allow the guest to pass an input parameter block of up to > > 112 bytes. Hyper-V can also return data back to the guest in the > > remaining XMM registers that are not used by the current hypercall. > > > > Add framework to read/write to XMM registers in kvm_hv_hypercall() and > > use the additional hypercall inputs from XMM registers in > > kvm_hv_flush_tlb() when possible. > > > > Cc: Alexander Graf > > Co-developed-by: Evgeny Iakovlev > > Signed-off-by: Evgeny Iakovlev > > Signed-off-by: Siddharth Chandrasekaran > > --- > > arch/x86/kvm/hyperv.c | 109 ++++++++++++++++++++++++++++++++++-------- > > 1 file changed, 90 insertions(+), 19 deletions(-) > > > > diff --git a/arch/x86/kvm/hyperv.c b/arch/x86/kvm/hyperv.c > > index 8f6babd1ea0d..1f9959aba70d 100644 > > --- a/arch/x86/kvm/hyperv.c > > +++ b/arch/x86/kvm/hyperv.c > > @@ -36,6 +36,7 @@ > > > > #include "trace.h" > > #include "irq.h" > > +#include "fpu.h" > > > > /* "Hv#1" signature */ > > #define HYPERV_CPUID_SIGNATURE_EAX 0x31237648 > > @@ -1623,6 +1624,8 @@ static __always_inline unsigned long *sparse_set_to_vcpu_mask( > > return vcpu_bitmap; > > } > > > > +#define KVM_HV_HYPERCALL_MAX_XMM_REGISTERS 6 > > Nitpick: this is not KVM-specific so could probably go to arch/x86/include/asm/hyperv-tlfs.h Ack. > > + > > struct kvm_hv_hcall { > > u64 param; > > u64 ingpa; > > @@ -1632,10 +1635,14 @@ struct kvm_hv_hcall { > > u16 rep_idx; > > bool fast; > > bool rep; > > + sse128_t xmm[KVM_HV_HYPERCALL_MAX_XMM_REGISTERS]; > > + bool xmm_dirty; > > }; > > > > static u64 kvm_hv_flush_tlb(struct kvm_vcpu *vcpu, struct kvm_hv_hcall *hc, bool ex) > > { > > + int i, j; > > + gpa_t gpa; > > struct kvm *kvm = vcpu->kvm; > > struct kvm_vcpu_hv *hv_vcpu = to_hv_vcpu(vcpu); > > struct hv_tlb_flush_ex flush_ex; > > @@ -1649,8 +1656,15 @@ static u64 kvm_hv_flush_tlb(struct kvm_vcpu *vcpu, struct kvm_hv_hcall *hc, bool > > bool all_cpus; > > > > if (!ex) { > > - if (unlikely(kvm_read_guest(kvm, hc->ingpa, &flush, sizeof(flush)))) > > - return HV_STATUS_INVALID_HYPERCALL_INPUT; > > + if (hc->fast) { > > + flush.address_space = hc->ingpa; > > + flush.flags = hc->outgpa; > > + flush.processor_mask = sse128_lo(hc->xmm[0]); > > + } else { > > + if (unlikely(kvm_read_guest(kvm, hc->ingpa, > > + &flush, sizeof(flush)))) > > + return HV_STATUS_INVALID_HYPERCALL_INPUT; > > + } > > > > trace_kvm_hv_flush_tlb(flush.processor_mask, > > flush.address_space, flush.flags); > > @@ -1668,9 +1682,16 @@ static u64 kvm_hv_flush_tlb(struct kvm_vcpu *vcpu, struct kvm_hv_hcall *hc, bool > > all_cpus = (flush.flags & HV_FLUSH_ALL_PROCESSORS) || > > flush.processor_mask == 0; > > } else { > > - if (unlikely(kvm_read_guest(kvm, hc->ingpa, &flush_ex, > > - sizeof(flush_ex)))) > > - return HV_STATUS_INVALID_HYPERCALL_INPUT; > > + if (hc->fast) { > > + flush_ex.address_space = hc->ingpa; > > + flush_ex.flags = hc->outgpa; > > + memcpy(&flush_ex.hv_vp_set, > > + &hc->xmm[0], sizeof(hc->xmm[0])); > > + } else { > > + if (unlikely(kvm_read_guest(kvm, hc->ingpa, &flush_ex, > > + sizeof(flush_ex)))) > > + return HV_STATUS_INVALID_HYPERCALL_INPUT; > > + } > > > > trace_kvm_hv_flush_tlb_ex(flush_ex.hv_vp_set.valid_bank_mask, > > flush_ex.hv_vp_set.format, > > @@ -1681,20 +1702,29 @@ static u64 kvm_hv_flush_tlb(struct kvm_vcpu *vcpu, struct kvm_hv_hcall *hc, bool > > all_cpus = flush_ex.hv_vp_set.format != > > HV_GENERIC_SET_SPARSE_4K; > > > > - sparse_banks_len = > > - bitmap_weight((unsigned long *)&valid_bank_mask, 64) * > > - sizeof(sparse_banks[0]); > > + sparse_banks_len = bitmap_weight((unsigned long *)&valid_bank_mask, 64); > > > > if (!sparse_banks_len && !all_cpus) > > goto ret_success; > > > > - if (!all_cpus && > > - kvm_read_guest(kvm, > > - hc->ingpa + offsetof(struct hv_tlb_flush_ex, > > - hv_vp_set.bank_contents), > > - sparse_banks, > > - sparse_banks_len)) > > - return HV_STATUS_INVALID_HYPERCALL_INPUT; > > + if (!all_cpus) { > > + if (hc->fast) { > > + if (sparse_banks_len > KVM_HV_HYPERCALL_MAX_XMM_REGISTERS - 1) > > + return HV_STATUS_INVALID_HYPERCALL_INPUT; > > + for (i = 0, j = 1; i < sparse_banks_len; i += 2, j++) { > > Nitpick: you don't really need 'j' here as 'j == i/2 + 1', right? Yes, you are right. Changed. > > + sparse_banks[i + 0] = sse128_lo(hc->xmm[j]); > > Using ' + 0' for identation is ... unusual :-) I'm not opposed to it > here though. Old habit :-). > > + sparse_banks[i + 1] = sse128_hi(hc->xmm[j]); > > + } > > + } else { > > + gpa = hc->ingpa; > > + gpa += offsetof(struct hv_tlb_flush_ex, > > + hv_vp_set.bank_contents); > > Nitpick: if splitting these into two lines is only done to fit into 80 > chars then I'd the requirement is no more so we can be a bit wider. > > gpa = hc->ingpa + offsetof(...) Ack. > > + if (unlikely(kvm_read_guest(kvm, gpa, sparse_banks, > > + sparse_banks_len * > > + sizeof(sparse_banks[0])))) > > + return HV_STATUS_INVALID_HYPERCALL_INPUT; > > + } > > + } > > } > > > > cpumask_clear(&hv_vcpu->tlb_flush); > > @@ -1890,6 +1920,41 @@ static u16 kvm_hvcall_signal_event(struct kvm_vcpu *vcpu, struct kvm_hv_hcall *h > > return HV_STATUS_SUCCESS; > > } > > > > +static bool is_xmm_fast_hypercall(struct kvm_hv_hcall *hc) > > +{ > > + switch (hc->code) { > > + case HVCALL_FLUSH_VIRTUAL_ADDRESS_LIST: > > + case HVCALL_FLUSH_VIRTUAL_ADDRESS_SPACE: > > + case HVCALL_FLUSH_VIRTUAL_ADDRESS_LIST_EX: > > + case HVCALL_FLUSH_VIRTUAL_ADDRESS_SPACE_EX: > > + return true; > > + } > > + > > + return false; > > +} > > + > > +static inline void kvm_hv_hypercall_read_xmm(struct kvm_hv_hcall *hc) > > +{ > > + int reg; > > + > > + kvm_fpu_get(); > > + for (reg = 0; reg < KVM_HV_HYPERCALL_MAX_XMM_REGISTERS; reg++) > > + _kvm_read_sse_reg(reg, &hc->xmm[reg]); > > + kvm_fpu_put(); > > + hc->xmm_dirty = false; > > +} > > + > > +static inline void kvm_hv_hypercall_write_xmm(struct kvm_hv_hcall *hc) > > +{ > > + int reg; > > + > > + kvm_fpu_get(); > > + for (reg = 0; reg < KVM_HV_HYPERCALL_MAX_XMM_REGISTERS; reg++) > > + _kvm_write_sse_reg(reg, &hc->xmm[reg]); > > + kvm_fpu_put(); > > + hc->xmm_dirty = false; > > +} > > + > > int kvm_hv_hypercall(struct kvm_vcpu *vcpu) > > { > > struct kvm_hv_hcall hc; > > @@ -1926,6 +1991,9 @@ int kvm_hv_hypercall(struct kvm_vcpu *vcpu) > > hc.rep_idx = (hc.param >> HV_HYPERCALL_REP_START_OFFSET) & 0xfff; > > hc.rep = !!(hc.rep_cnt || hc.rep_idx); > > > > + if (hc.fast && is_xmm_fast_hypercall(&hc)) > > + kvm_hv_hypercall_read_xmm(&hc); > > + > > trace_kvm_hv_hypercall(hc.code, hc.fast, hc.rep_cnt, hc.rep_idx, > > hc.ingpa, hc.outgpa); > > > > @@ -1961,28 +2029,28 @@ int kvm_hv_hypercall(struct kvm_vcpu *vcpu) > > kvm_hv_hypercall_complete_userspace; > > return 0; > > case HVCALL_FLUSH_VIRTUAL_ADDRESS_LIST: > > - if (unlikely(hc.fast || !hc.rep_cnt || hc.rep_idx)) { > > + if (unlikely(!hc.rep_cnt || hc.rep_idx)) { > > ret = HV_STATUS_INVALID_HYPERCALL_INPUT; > > break; > > } > > ret = kvm_hv_flush_tlb(vcpu, &hc, false); > > break; > > case HVCALL_FLUSH_VIRTUAL_ADDRESS_SPACE: > > - if (unlikely(hc.fast || hc.rep)) { > > + if (unlikely(hc.rep)) { > > ret = HV_STATUS_INVALID_HYPERCALL_INPUT; > > break; > > } > > ret = kvm_hv_flush_tlb(vcpu, &hc, false); > > break; > > case HVCALL_FLUSH_VIRTUAL_ADDRESS_LIST_EX: > > - if (unlikely(hc.fast || !hc.rep_cnt || hc.rep_idx)) { > > + if (unlikely(!hc.rep_cnt || hc.rep_idx)) { > > ret = HV_STATUS_INVALID_HYPERCALL_INPUT; > > break; > > } > > ret = kvm_hv_flush_tlb(vcpu, &hc, true); > > break; > > case HVCALL_FLUSH_VIRTUAL_ADDRESS_SPACE_EX: > > - if (unlikely(hc.fast || hc.rep)) { > > + if (unlikely(hc.rep)) { > > ret = HV_STATUS_INVALID_HYPERCALL_INPUT; > > break; > > } > > @@ -2035,6 +2103,9 @@ int kvm_hv_hypercall(struct kvm_vcpu *vcpu) > > break; > > } > > > > + if (hc.xmm_dirty) > > + kvm_hv_hypercall_write_xmm(&hc); > > + > > Wei already mention that but as 'xmm_dirty' is not being used in this > patch I'd suggest we move it out too. Okay, I should remove HV_X64_HYPERCALL_XMM_OUTPUT_AVAILABLE for now then. ~ Sid. Amazon Development Center Germany GmbH Krausenstr. 38 10117 Berlin Geschaeftsfuehrung: Christian Schlaeger, Jonathan Weiss Eingetragen am Amtsgericht Charlottenburg unter HRB 149173 B Sitz: Berlin Ust-ID: DE 289 237 879