From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-pj1-f73.google.com (mail-pj1-f73.google.com [209.85.216.73]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id F008312D753 for ; Wed, 12 Jun 2024 21:02:59 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.216.73 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1718226181; cv=none; b=Fn6Z2zYUd2Pv78amAWmnvzcoXsDyP9OQnFYi/YISbtyjA9+2QOiFsWhzdCA8UXbga0SfJzLFP5KHyrV8ShrjTmFhMQFfmXyqqFb0FG2jWdaDtWJvNclIXhTevFflA3rlFhDml40V8WjjGtlKdH8+qR3t7LnXk+woIY21GAUaO1o= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1718226181; c=relaxed/simple; bh=1TYIkyImVcWQGBXXHpL6wbMEynsMIkTMy8d3F8mZSP0=; h=Date:In-Reply-To:Mime-Version:References:Message-ID:Subject:From: To:Cc:Content-Type; b=f2aO5NMrcRBuuJBdrYKqz4XVOg8b5gPQ/gW3Vf48lz30B5hDd92+ooRGXIaO/zoZyw76nXO9rscRatKmeJv5G7vesMt1idncbeL2OkwuDFL0wppoBwwydGaOv4ZSKNnaRZYoDZkL4SQs2W3H5jo5LXR6Vy2XBYTMNsoD/3wiG3Y= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com; spf=pass smtp.mailfrom=flex--seanjc.bounces.google.com; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b=bW+jOPvr; arc=none smtp.client-ip=209.85.216.73 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=flex--seanjc.bounces.google.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="bW+jOPvr" Received: by mail-pj1-f73.google.com with SMTP id 98e67ed59e1d1-2c2d6e09e62so182989a91.2 for ; Wed, 12 Jun 2024 14:02:59 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20230601; t=1718226179; x=1718830979; darn=vger.kernel.org; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:from:to:cc:subject:date:message-id:reply-to; bh=J3xgWRxCgfKePUIQRk1/bOVRKkSjNiVa6+ku2rMooqI=; b=bW+jOPvrXWc2sN7IGlpVQaq8Zx9w7YW/aPk2UtDiT5Ev/7RR4PBWThSAVJj2YUDWRc DzZPTEKxCvRVYPLZhpe3TtAKgdcGC/+/RHJzfhYp+pGRQpTghRtTT2JI8UaX1Sd76jLV vr/A8JrJkoMVkydXTRobtq8LpBQAdfymeE6FfSXk3PszR5JUMX+vyYxe1CDeZIuZ48bs LDauAl6Lh25UP03oml8RjZFoEpfLnxRNBjTscaAZmDGCu2M6+7GL6c+vDyl34WHNY/lB 5OWD3pd0J/Tt+xyWyh+m2PSJr4I4h69C5Q+hTk+rr69c0qnSUiF/Uoh18pmMixeO0aF0 43ww== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1718226179; x=1718830979; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=J3xgWRxCgfKePUIQRk1/bOVRKkSjNiVa6+ku2rMooqI=; b=bfUrwpIf5Yh77owVuFma94QYycH5O2svHaUo895v2dRz2Ais77uzWml8C8xOrzhj7H f+wTlwl6ZXZkUHtdbpSFnyhFOkRZKpZpHNVdY89AztJWTYDSdWa1RJoUZ4Z8T3XEta33 5AR4Gv008o70Ec3uZb0hV3ERCuTwuGg9rUgMrfSM9bu+YjYUd06tduKeXWhJwT1SdY8W AsIV1+YVxDSiUW6YGQnmM3Vrw+9E7xZVn6FJ3zrOKnApExgu3CRmCvQg/oJ3sOKIii48 HrK3zUypMg5BQ538B7GuNhPPINZBt+X1VEuxnlO73xYq1WzDsIWLrfGDcShLda+XIGpn 2FQw== X-Forwarded-Encrypted: i=1; AJvYcCUKoi02NlXEfJyvUQrVLTP0e1Jd5ias7Tei6qPwFHcc4m+ZSSQfP8WK78zjACO8VATjUaWAf/N+reV7HDpzh9JLcL3sMw3RcjZDEJJl X-Gm-Message-State: AOJu0YzVJcNXxowbGIeirsj/RbCM8I4jLQ01YF6StKobYMJCgG2jwsy1 fg/rHP1qM4srN7jJdKT1zTYT1pbGts11IVfRqpDfFlBo9uVq1dRzUr2KDbmBzJCurpAhse5fgT7 9Yw== X-Google-Smtp-Source: AGHT+IHtBONcZJ3ua6rr9KF0YTE06FmHu2WTAWj/KJP5w7j/Ttnoq6SE0bp0Q5inkEDQ0elbifO9mus7g/Y= X-Received: from zagreus.c.googlers.com ([fda3:e722:ac3:cc00:7f:e700:c0a8:5c37]) (user=seanjc job=sendgmr) by 2002:a17:90a:62c9:b0:2c2:c65f:52dc with SMTP id 98e67ed59e1d1-2c4a770e8f6mr8383a91.6.1718226179078; Wed, 12 Jun 2024 14:02:59 -0700 (PDT) Date: Wed, 12 Jun 2024 14:02:57 -0700 In-Reply-To: Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 References: <20240419085927.3648704-1-pbonzini@redhat.com> <20240419085927.3648704-6-pbonzini@redhat.com> Message-ID: Subject: Re: [PATCH 5/6] KVM: x86: Implement kvm_arch_vcpu_pre_fault_memory() From: Sean Christopherson To: Xiaoyao Li Cc: Paolo Bonzini , linux-kernel@vger.kernel.org, kvm@vger.kernel.org, isaku.yamahata@intel.com, binbin.wu@linux.intel.com, rick.p.edgecombe@intel.com Content-Type: text/plain; charset="us-ascii" On Mon, Apr 22, 2024, Xiaoyao Li wrote: > On 4/19/2024 4:59 PM, Paolo Bonzini wrote: > > diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c > > index 10e90788b263..a045b23964c0 100644 > > --- a/arch/x86/kvm/mmu/mmu.c > > +++ b/arch/x86/kvm/mmu/mmu.c > > @@ -4647,6 +4647,78 @@ int kvm_tdp_page_fault(struct kvm_vcpu *vcpu, struct kvm_page_fault *fault) > > return direct_page_fault(vcpu, fault); > > } > > +static int kvm_tdp_map_page(struct kvm_vcpu *vcpu, gpa_t gpa, u64 error_code, > > + u8 *level) Align parameters: static int kvm_tdp_map_page(struct kvm_vcpu *vcpu, gpa_t gpa, u64 error_code, u8 *level) > > +{ > > + int r; > > + > > + /* Restrict to TDP page fault. */ This is fairly obvious from the code, what might not be obvious is _why_. I'm also ok dropping the comment entirely, but it's easy enough to provide a hint to the reader. > > + if (vcpu->arch.mmu->page_fault != kvm_tdp_page_fault) > > + return -EOPNOTSUPP; > > + > > +retry: > > + r = __kvm_mmu_do_page_fault(vcpu, gpa, error_code, true, NULL, level); > > + if (r < 0) > > + return r; > > + > > + switch (r) { > > + case RET_PF_RETRY: > > + if (signal_pending(current)) > > + return -EINTR; > > + cond_resched(); > > + goto retry; Rather than a goto+retry from inside a switch statement, what about: int r; /* * Pre-faulting a GPA is supported only non-nested TDP, as indirect * MMUs map either GVAs or L2 GPAs, not L1 GPAs. */ if (vcpu->arch.mmu->page_fault != kvm_tdp_page_fault) return -EOPNOTSUPP; do { if (signal_pending(current)) return -EINTR; cond_resched(); r = kvm_mmu_do_page_fault(vcpu, gpa, error_code, true, NULL, level); } while (r == RET_PF_RETRY); switch (r) { case RET_PF_FIXED: case RET_PF_SPURIOUS: break; case RET_PF_EMULATE: return -ENOENT; case RET_PF_CONTINUE: case RET_PF_INVALID: case RET_PF_RETRY: default: WARN_ON_ONCE(r >= 0); return -EIO; } return 0;