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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id D346FC19F2C for ; Tue, 2 Aug 2022 09:54:48 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S236246AbiHBJyq (ORCPT ); Tue, 2 Aug 2022 05:54:46 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:39082 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235730AbiHBJyo (ORCPT ); Tue, 2 Aug 2022 05:54:44 -0400 Received: from out2.migadu.com (out2.migadu.com [IPv6:2001:41d0:2:aacc::]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 3A8C117049; Tue, 2 Aug 2022 02:54:40 -0700 (PDT) Date: Tue, 2 Aug 2022 11:54:37 +0200 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.dev; s=key1; t=1659434078; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=wa5eejjtGHxSUyoNdwZTsoUHFpSlVjk6Jt5se0ltnss=; b=QWGNOJiq16w0VexMaO+QC94HrmuAuandBis6QRXv+3Zs8Qd+GlBWTvUrf1u8U0iOAnDymI B/PSYL+4SGSK7By4ByLJUuBpru1gSblLk2ABxOxtev6nIH7G52keuz/oYI99MiScF/yq0Q ZkDAi2Ovz5JSjH8uKW5t5LlyckUYjQ8= X-Report-Abuse: Please report any abuse attempt to abuse@migadu.com and include these headers. From: Andrew Jones To: Peter Gonda Cc: kvm@vger.kernel.org, linux-kernel@vger.kernel.org, marcorr@google.com, seanjc@google.com, michael.roth@amd.com, thomas.lendacky@amd.com, joro@8bytes.org, mizhang@google.com, pbonzini@redhat.com Subject: Re: [V2 07/11] KVM: selftests: Consolidate boilerplate code in get_ucall() Message-ID: <20220802095437.fbho3bwgs3yi3fur@kamzik> References: <20220801201109.825284-1-pgonda@google.com> <20220801201109.825284-8-pgonda@google.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20220801201109.825284-8-pgonda@google.com> X-Migadu-Flow: FLOW_OUT X-Migadu-Auth-User: linux.dev Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Aug 01, 2022 at 01:11:05PM -0700, Peter Gonda wrote: > From: Sean Christopherson > > Consolidate the actual copying of a ucall struct from guest=>host into > the common get_ucall(). Return a host virtual address instead of a guest > virtual address even though the addr_gva2hva() part could be moved to > get_ucall() too. Conceptually, get_ucall() is invoked from the host and > should return a host virtual address (and returning NULL for "nothing to > see here" is far superior to returning 0). The code does not match this description anymore, now that ucall_arch_get_ucall() returns a gva (as a uint64_t), but the description is good, the code is wrong. Please restore the spirit of Sean's patch (particularly because it still says it's from Sean...) Thanks, drew > > Use pointer shenanigans instead of an unnecessary bounce buffer when the > caller of get_ucall() provides a valid pointer. > > Signed-off-by: Sean Christopherson > Signed-off-by: Peter Gonda > --- > .../selftests/kvm/include/ucall_common.h | 8 ++------ > .../testing/selftests/kvm/lib/aarch64/ucall.c | 13 +++---------- > tools/testing/selftests/kvm/lib/riscv/ucall.c | 19 +++---------------- > tools/testing/selftests/kvm/lib/s390x/ucall.c | 16 +++------------- > .../testing/selftests/kvm/lib/ucall_common.c | 19 +++++++++++++++++++ > .../testing/selftests/kvm/lib/x86_64/ucall.c | 16 +++------------- > 6 files changed, 33 insertions(+), 58 deletions(-) > > diff --git a/tools/testing/selftests/kvm/include/ucall_common.h b/tools/testing/selftests/kvm/include/ucall_common.h > index 5a85f5318bbe..c1bc8e33ef3f 100644 > --- a/tools/testing/selftests/kvm/include/ucall_common.h > +++ b/tools/testing/selftests/kvm/include/ucall_common.h > @@ -27,9 +27,10 @@ struct ucall { > void ucall_arch_init(struct kvm_vm *vm, void *arg); > void ucall_arch_uninit(struct kvm_vm *vm); > void ucall_arch_do_ucall(vm_vaddr_t uc); > -uint64_t ucall_arch_get_ucall(struct kvm_vcpu *vcpu, struct ucall *uc); > +uint64_t ucall_arch_get_ucall(struct kvm_vcpu *vcpu); > > void ucall(uint64_t cmd, int nargs, ...); > +uint64_t get_ucall(struct kvm_vcpu *vcpu, struct ucall *uc); > > static inline void ucall_init(struct kvm_vm *vm, void *arg) > { > @@ -41,11 +42,6 @@ static inline void ucall_uninit(struct kvm_vm *vm) > ucall_arch_uninit(vm); > } > > -static inline uint64_t get_ucall(struct kvm_vcpu *vcpu, struct ucall *uc) > -{ > - return ucall_arch_get_ucall(vcpu, uc); > -} > - > #define GUEST_SYNC_ARGS(stage, arg1, arg2, arg3, arg4) \ > ucall(UCALL_SYNC, 6, "hello", stage, arg1, arg2, arg3, arg4) > #define GUEST_SYNC(stage) ucall(UCALL_SYNC, 2, "hello", stage) > diff --git a/tools/testing/selftests/kvm/lib/aarch64/ucall.c b/tools/testing/selftests/kvm/lib/aarch64/ucall.c > index 1c81a6a5c1f2..d2f099caa9ab 100644 > --- a/tools/testing/selftests/kvm/lib/aarch64/ucall.c > +++ b/tools/testing/selftests/kvm/lib/aarch64/ucall.c > @@ -78,24 +78,17 @@ void ucall_arch_do_ucall(vm_vaddr_t uc) > uint64_t ucall_arch_get_ucall(struct kvm_vcpu *vcpu, struct ucall *uc) > { > struct kvm_run *run = vcpu->run; > - struct ucall ucall = {}; > - > - if (uc) > - memset(uc, 0, sizeof(*uc)); > > if (run->exit_reason == KVM_EXIT_MMIO && > run->mmio.phys_addr == (uint64_t)ucall_exit_mmio_addr) { > - vm_vaddr_t gva; > + uint64_t ucall_addr; > > TEST_ASSERT(run->mmio.is_write && run->mmio.len == 8, > "Unexpected ucall exit mmio address access"); > memcpy(&gva, run->mmio.data, sizeof(gva)); > - memcpy(&ucall, addr_gva2hva(vcpu->vm, gva), sizeof(ucall)); > > - vcpu_run_complete_io(vcpu); > - if (uc) > - memcpy(uc, &ucall, sizeof(ucall)); > + return ucall_addr; > } > > - return ucall.cmd; > + return 0; > } > diff --git a/tools/testing/selftests/kvm/lib/riscv/ucall.c b/tools/testing/selftests/kvm/lib/riscv/ucall.c > index b1598f418c1f..3f000d0b705f 100644 > --- a/tools/testing/selftests/kvm/lib/riscv/ucall.c > +++ b/tools/testing/selftests/kvm/lib/riscv/ucall.c > @@ -51,27 +51,15 @@ void ucall_arch_do_ucall(vm_vaddr_t uc) > uc, 0, 0, 0, 0, 0); > } > > -uint64_t ucall_arch_get_ucall(struct kvm_vcpu *vcpu, struct ucall *uc) > +uint64_t ucall_arch_get_ucall(struct kvm_vcpu *vcpu) > { > struct kvm_run *run = vcpu->run; > - struct ucall ucall = {}; > - > - if (uc) > - memset(uc, 0, sizeof(*uc)); > > if (run->exit_reason == KVM_EXIT_RISCV_SBI && > run->riscv_sbi.extension_id == KVM_RISCV_SELFTESTS_SBI_EXT) { > switch (run->riscv_sbi.function_id) { > case KVM_RISCV_SELFTESTS_SBI_UCALL: > - memcpy(&ucall, > - addr_gva2hva(vcpu->vm, run->riscv_sbi.args[0]), > - sizeof(ucall)); > - > - vcpu_run_complete_io(vcpu); > - if (uc) > - memcpy(uc, &ucall, sizeof(ucall)); > - > - break; > + return vcpu->vm, run->riscv_sbi.args[0]; > case KVM_RISCV_SELFTESTS_SBI_UNEXP: > vcpu_dump(stderr, vcpu, 2); > TEST_ASSERT(0, "Unexpected trap taken by guest"); > @@ -80,6 +68,5 @@ uint64_t ucall_arch_get_ucall(struct kvm_vcpu *vcpu, struct ucall *uc) > break; > } > } > - > - return ucall.cmd; > + return 0; > } > diff --git a/tools/testing/selftests/kvm/lib/s390x/ucall.c b/tools/testing/selftests/kvm/lib/s390x/ucall.c > index 114cb4af295f..f7a5a7eb4aa8 100644 > --- a/tools/testing/selftests/kvm/lib/s390x/ucall.c > +++ b/tools/testing/selftests/kvm/lib/s390x/ucall.c > @@ -20,13 +20,9 @@ void ucall_arch_do_ucall(vm_vaddr_t uc) > asm volatile ("diag 0,%0,0x501" : : "a"(uc) : "memory"); > } > > -uint64_t ucall_arch_get_ucall(struct kvm_vcpu *vcpu, struct ucall *uc) > +uint64_t ucall_arch_get_ucall(struct kvm_vcpu *vcpu) > { > struct kvm_run *run = vcpu->run; > - struct ucall ucall = {}; > - > - if (uc) > - memset(uc, 0, sizeof(*uc)); > > if (run->exit_reason == KVM_EXIT_S390_SIEIC && > run->s390_sieic.icptcode == 4 && > @@ -34,13 +30,7 @@ uint64_t ucall_arch_get_ucall(struct kvm_vcpu *vcpu, struct ucall *uc) > (run->s390_sieic.ipb >> 16) == 0x501) { > int reg = run->s390_sieic.ipa & 0xf; > > - memcpy(&ucall, addr_gva2hva(vcpu->vm, run->s.regs.gprs[reg]), > - sizeof(ucall)); > - > - vcpu_run_complete_io(vcpu); > - if (uc) > - memcpy(uc, &ucall, sizeof(ucall)); > + return run->s.regs.gprs[reg]; > } > - > - return ucall.cmd; > + return 0; > } > diff --git a/tools/testing/selftests/kvm/lib/ucall_common.c b/tools/testing/selftests/kvm/lib/ucall_common.c > index 749ffdf23855..a060252bab40 100644 > --- a/tools/testing/selftests/kvm/lib/ucall_common.c > +++ b/tools/testing/selftests/kvm/lib/ucall_common.c > @@ -18,3 +18,22 @@ void ucall(uint64_t cmd, int nargs, ...) > > ucall_arch_do_ucall((vm_vaddr_t)&uc); > } > + > +uint64_t get_ucall(struct kvm_vcpu *vcpu, struct ucall *uc) > +{ > + struct ucall ucall; > + void *addr; > + > + if (!uc) > + uc = &ucall; > + > + addr = addr_gva2hva(vcpu->vm, ucall_arch_get_ucall(vcpu)); > + if (addr) { > + memcpy(uc, addr, sizeof(*uc)); > + vcpu_run_complete_io(vcpu); > + } else { > + memset(uc, 0, sizeof(*uc)); > + } > + > + return uc->cmd; > +} > diff --git a/tools/testing/selftests/kvm/lib/x86_64/ucall.c b/tools/testing/selftests/kvm/lib/x86_64/ucall.c > index 9f532dba1003..24746120a593 100644 > --- a/tools/testing/selftests/kvm/lib/x86_64/ucall.c > +++ b/tools/testing/selftests/kvm/lib/x86_64/ucall.c > @@ -22,25 +22,15 @@ void ucall_arch_do_ucall(vm_vaddr_t uc) > : : [port] "d" (UCALL_PIO_PORT), "D" (uc) : "rax", "memory"); > } > > -uint64_t ucall_arch_get_ucall(struct kvm_vcpu *vcpu, struct ucall *uc) > +uint64_t ucall_arch_get_ucall(struct kvm_vcpu *vcpu) > { > struct kvm_run *run = vcpu->run; > - struct ucall ucall = {}; > - > - if (uc) > - memset(uc, 0, sizeof(*uc)); > > if (run->exit_reason == KVM_EXIT_IO && run->io.port == UCALL_PIO_PORT) { > struct kvm_regs regs; > > vcpu_regs_get(vcpu, ®s); > - memcpy(&ucall, addr_gva2hva(vcpu->vm, (vm_vaddr_t)regs.rdi), > - sizeof(ucall)); > - > - vcpu_run_complete_io(vcpu); > - if (uc) > - memcpy(uc, &ucall, sizeof(ucall)); > + return regs.rdi; > } > - > - return ucall.cmd; > + return 0; > } > -- > 2.37.1.455.g008518b4e5-goog >