From patchwork Tue Apr 30 19:31:53 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Sean Christopherson X-Patchwork-Id: 13649895 Received: from mail-pj1-f74.google.com (mail-pj1-f74.google.com [209.85.216.74]) (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 B6826194C9D for ; Tue, 30 Apr 2024 19:32:00 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.216.74 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1714505522; cv=none; b=ojbE1aJaHI1CSFvaP4sHTFV4Q4W/jL6E6bQ0dYELtmtj8HvTWKFigzx5Ote+YKiA3hhewpCFHOeUUuTSx/ppDyn/wn/9w7/1Ne1+8L2XGpIDyn38mSWEfXgAqVZpgVAtVYF0C/cu1jsqyKufyp5F0YAvYBl2SLTN4GpxYnirnzA= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1714505522; c=relaxed/simple; bh=ZyEi6X5pCM2tp1slqyp4M7rxWVN5czCX48iQBtE7Jeo=; h=Date:Mime-Version:Message-ID:Subject:From:To:Cc:Content-Type; b=Eb4T1+AKV34EDmstbOz/VcGDlRxJO4sYYQqFdZvLUIo96Bv8YIe9EG+SDGHM1cROc4m/vSiZDZaXecAarb+rgDxpUAa0IC5DbnChKnAOz0zZn/Yqrlu7iPenXQPs57BIcCx9VmuoXde66+/1jyfjqHujIxLNGxTLszkZVcZa0Ow= 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=pVbL//pF; arc=none smtp.client-ip=209.85.216.74 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="pVbL//pF" Received: by mail-pj1-f74.google.com with SMTP id 98e67ed59e1d1-2ac3403b27eso6941949a91.0 for ; Tue, 30 Apr 2024 12:32:00 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20230601; t=1714505520; x=1715110320; darn=vger.kernel.org; h=cc:to:from:subject:message-id:mime-version:date:reply-to:from:to:cc :subject:date:message-id:reply-to; bh=z8cKIw53BRkz+z0+cac0VztUPzZ2bkNPe6LEvW4OcBU=; b=pVbL//pFn986soxarrKWGavPTzgb+nNosoRNSY7l4l+G7TXLTTPIsqVy8S3fRMOrGx kA2WtNhsSfmZ8NcJzpm58DPU4GvSzS5zOWDpMS1TXtzBDUKj6FnNzV4y8GIseweI3tc0 mRilImRhOjk+WS3GLE2oARsGeH2N+K+ydBVllC/04KBn8mo7ItfLZDDNV+4gTNZTXzIF i5unsMQpZ7x15jTxb16NJohmtPwvwBbUKRRn9tO4eQA+EUQbUZiXKKkW2d0md3MwuaDn 7JAJbATuYkYYWeLAWcESPrNuFQi+T4uS9aUddK0FrbVNayrWHJI/GKqZHg0LGOYZMhXq xcGw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1714505520; x=1715110320; h=cc:to:from:subject:message-id:mime-version:date:reply-to :x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=z8cKIw53BRkz+z0+cac0VztUPzZ2bkNPe6LEvW4OcBU=; b=lVFRBIWBDK+Nh7lybrPvGeFq+Um83veBY0XNX2jfi/W6MBaIO5x2wW1nr4DUekJC3I lRcFmTlQ+JDE75rHUX4jXBaanWFnRrKKEU1NFoxzffHy3dgmjbshSGTLUQQgjXAJPab1 PFzqiX+HN51+3MllTEliPOlnZ7XDVU0vQQrY8kJLxAByN/Ld0R4ZRIfHnfO0UvGyfIBE P8EDjIrAJR0lWQKw3vzNS+UDmFVxHDN1PAoev/qlWPJaSDHEyoMgx01qCde14vHu1Dmc NGh0a8qSysMHGxr6cf2i8ClzZc2ZnTKF8GVSi/VVWzkxXQv4gJfcMRYFb7ffTnXHj57q MVDA== X-Forwarded-Encrypted: i=1; AJvYcCXyEKvFok9ZEdE2CY5z3zV29y1Ht/KGqtW+Wg3+s0fMJTE6typg7gGo3608WC6WkB9pn/VsIjH5ySfdZPENe0QIGgyB X-Gm-Message-State: AOJu0Yxcc1oYXFXDXPRB/Eh258CNLPW/QMlyneWHrqEaIgrxrMYs5rfQ FpYKligPTHTLpz5I7Em6Io+PdFScztfVV9YS8n+Dakp+fxwKgvo3iypGRYm9jk4CkHfqM7RhIKE uuA== X-Google-Smtp-Source: AGHT+IH3JUNqnUxIpxTDCx/ljNN0s2y6mLqDYiJH9gncvZUrZrTQ/cL7Kjz1TcqYgEZ6lTuIQ7azs+1F9y4= X-Received: from zagreus.c.googlers.com ([fda3:e722:ac3:cc00:7f:e700:c0a8:5c37]) (user=seanjc job=sendgmr) by 2002:a17:90a:e504:b0:2a2:ff01:dd7c with SMTP id t4-20020a17090ae50400b002a2ff01dd7cmr1190pjy.8.1714505520000; Tue, 30 Apr 2024 12:32:00 -0700 (PDT) Reply-To: Sean Christopherson Date: Tue, 30 Apr 2024 12:31:53 -0700 Precedence: bulk X-Mailing-List: kvm@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 X-Mailer: git-send-email 2.45.0.rc0.197.gbae5840b3b-goog Message-ID: <20240430193157.419425-1-seanjc@google.com> Subject: [PATCH 0/4] KVM: Fold kvm_arch_sched_in() into kvm_arch_vcpu_load() From: Sean Christopherson To: Marc Zyngier , Oliver Upton , Tianrui Zhao , Bibo Mao , Huacai Chen , Michael Ellerman , Anup Patel , Paul Walmsley , Palmer Dabbelt , Albert Ou , Christian Borntraeger , Janosch Frank , Claudio Imbrenda , Sean Christopherson , Paolo Bonzini Cc: linux-arm-kernel@lists.infradead.org, kvmarm@lists.linux.dev, kvm@vger.kernel.org, loongarch@lists.linux.dev, linux-mips@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, kvm-riscv@lists.infradead.org, linux-riscv@lists.infradead.org, linux-kernel@vger.kernel.org Drop kvm_arch_sched_in() and instead pass a @sched_in boolean to kvm_arch_vcpu_load(). While fiddling with an idea for optimizing state management on AMD CPUs, I wanted to skip re-saving certain host state when a vCPU is scheduled back in, as the state (theoretically) shouldn't change for the task while it's scheduled out. Actually doing that was annoying and unnecessarily brittle due to having a separate API for the kvm_sched_in() case (the state save needed to be in kvm_arch_vcpu_load() for the common path). E.g. I could have set a "temporary"-ish flag somewhere in kvm_vcpu, but (a) that's gross and (b) it would rely on the arbitrary ordering between sched_in() and vcpu_load() staying the same. The only real downside I see is that arm64 and riscv end up having to pass "false" for their direct usage of kvm_arch_vcpu_load(), and passing boolean literals isn't ideal. But that can be solved by adding an inner helper that omits the @sched_in param (I almost added a patch to do that, but I couldn't convince myself it was necessary). The other motivation for this is to avoid yet another arch hook, and more arbitrary ordering, if there's a future need to hook kvm_sched_out() (we've come close on the x86 side several times). Sean Christopherson (4): KVM: Plumb in a @sched_in flag to kvm_arch_vcpu_load() KVM: VMX: Move PLE grow/shrink helpers above vmx_vcpu_load() KVM: x86: Fold kvm_arch_sched_in() into kvm_arch_vcpu_load() KVM: Delete the now unused kvm_arch_sched_in() arch/arm64/include/asm/kvm_host.h | 1 - arch/arm64/kvm/arm.c | 2 +- arch/arm64/kvm/emulate-nested.c | 4 +- arch/arm64/kvm/reset.c | 2 +- arch/loongarch/include/asm/kvm_host.h | 1 - arch/loongarch/kvm/vcpu.c | 2 +- arch/mips/include/asm/kvm_host.h | 1 - arch/mips/kvm/mmu.c | 2 +- arch/powerpc/include/asm/kvm_host.h | 1 - arch/powerpc/kvm/powerpc.c | 2 +- arch/riscv/include/asm/kvm_host.h | 1 - arch/riscv/kvm/vcpu.c | 4 +- arch/s390/include/asm/kvm_host.h | 1 - arch/s390/kvm/kvm-s390.c | 2 +- arch/x86/include/asm/kvm-x86-ops.h | 1 - arch/x86/include/asm/kvm_host.h | 4 +- arch/x86/kvm/pmu.c | 6 +-- arch/x86/kvm/svm/svm.c | 13 ++--- arch/x86/kvm/vmx/main.c | 2 - arch/x86/kvm/vmx/vmx.c | 75 +++++++++++++-------------- arch/x86/kvm/vmx/x86_ops.h | 3 +- arch/x86/kvm/x86.c | 26 +++++----- include/linux/kvm_host.h | 4 +- virt/kvm/kvm_main.c | 5 +- 24 files changed, 70 insertions(+), 95 deletions(-) base-commit: a96cb3bf390eebfead5fc7a2092f8452a7997d1b