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 A3234194C9F for ; Tue, 30 Apr 2024 19:32:00 +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=1714505522; cv=none; b=DakfcSXntN1D6CpS/f8oPDqAJ3lZS6waRar+G9YQUpPIrjfGTxVzyXRPwpR5pbqcNpTJ3qDNOjthovQtcCnBfMM8wsYkLCfh5a0Mi/Y8HUH6cYg7shuviRNEj0AiKiQCDoWJMfofQpl3ooFTbvWVWtb5dZT0YmCnyWVStXnon6I= 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=U4xgJoC7; 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="U4xgJoC7" Received: by mail-pj1-f73.google.com with SMTP id 98e67ed59e1d1-2ac3403b27eso6941950a91.0 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=lists.linux.dev; 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=U4xgJoC76UNfIkHovk+2fMq+7uKqdPttcJpIiw8pk/5+ufohLR2YcGgkUfVWcXZVhz jeq5pmvjE8qYKWIwWq16rt/VmQQrNZwnR99YYLwWzGactfuA/6otv6jul/R2i1qEcmc4 r4XLkUM4vuiv6nNNtnrCkWhFlWbAzh1ZbwjlkjQ+ShtzCfSQBALbO+AoFfNwGmjyxao6 CR29XB0qLiI2ufTXaveLpk8FTtDnYyyi8ceIgAk9JgECUIqDbUezVN/E0NbcZcZMBDZU NUwHrj0X/RaSOPy/VCkso+VpK9xraNuSBGODsep8XAGS6m1MgtNKkJL43uibNVtrQ2rq jMuQ== 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=WvpXrbV6EwjSZQ9SpbnsUog+pMI1zXh4rRglhEt3mRGrflXMHGVNGTdxXB/T957wfI OuGc5aNeiz3Kbe0Vcpg5A66qnLllo8kn1WXG/le6pU8TTsXHGUi4Um4S1fH7s8EJ/o6X KNC8jNKPBUEmFqXqh3x1/mnmaXchpdQVykpAajvQkiFzM95JTIX4slzzCrRh5x4em2zU FAwmL0Ah/fS11VdsQ5HxX3Q8BL+jgEO0SSFnXhvkIv1siDD1DAVABHQpU7jsSrwGkKbO j4RH7oca/2oxNAOexxEh78u3gioYAD/OgB4XfWZnmwALtVIi4+nsgl+30L+YTLDDg6hH PTmw== X-Forwarded-Encrypted: i=1; AJvYcCWHP0MPO3jTutie9JJvN07vvgbKYZPdcVMdJxDsMDvtWRKPp+1+2ulti5f3LiRz3KkEppcz6lCCGScjGQx0xZhTFzlvefaZ X-Gm-Message-State: AOJu0YycMT6ME8bhcPOr4MIL2tcggmFbWvAln6ZYsJTEIJ8iGYF1RsDg MkWlrdLoeX/fCYlDqoIhCG2yUQYNo1IuvxkOXJW237cGXHOCurJ4uaXH21R1pIGRA58berUdn91 Fww== 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: kvmarm@lists.linux.dev 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 Content-Type: text/plain; charset="UTF-8" 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 -- 2.45.0.rc0.197.gbae5840b3b-goog