From patchwork Fri Jul 19 23:50:57 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Sean Christopherson X-Patchwork-Id: 13737567 Received: from mail-pg1-f202.google.com (mail-pg1-f202.google.com [209.85.215.202]) (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 392FC1487FF for ; Fri, 19 Jul 2024 23:51:10 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.215.202 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1721433071; cv=none; b=XyuxCOQsWPBY0wXxTkqrM8fO6IFbzfgrGN/sQOFJBl2IP35PbLLQ/XJysubCbHKDasl1TRKHiQlsuwnfQ5XRIe+sgXVgdslXgap8BODRMVZ9uElbg+QySioIflaAzj4aQlW1iVV/uYah39QuZoBBThxKLafN+SRYRE6qTLtYtI0= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1721433071; c=relaxed/simple; bh=FyX1Xgj3fNg/YrI6oeFtEibrbeQf4Z27fJwh2HZVlS8=; h=Date:Mime-Version:Message-ID:Subject:From:To:Cc:Content-Type; b=IzSXMoJ2LgcOr7Ar50iTsBbu7jDm91biNj/d/a6BimMUgr3x4fmvqzCpgLMWyo1/fv/snL+FZSfBdwSVOZaomHrALNJtSyPeGuR1mdVbx33LnxynwIVvzgcq1KVSBfbv5pxdQUa7KEK4AJIJ7QjqoH6FdLjfLGnASJi32sfabj4= 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=CWL7IC8l; arc=none smtp.client-ip=209.85.215.202 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="CWL7IC8l" Received: by mail-pg1-f202.google.com with SMTP id 41be03b00d2f7-71cdcb122e8so2276441a12.2 for ; Fri, 19 Jul 2024 16:51:10 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20230601; t=1721433069; x=1722037869; 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=nQJLhJt+1v3X0AxqN/F0tmRwTbToicxjNz2Hd7wYOIk=; b=CWL7IC8leNkfbIAD1RVX2pm7RdUhaQAlfgnWVqtUhF7Mfi4mGK0dhHMijRsqt90YNT Jtz9rx+DLHbLaju1w23VM12uwqfPkpA/BbuL3aa8d9r65Dun4tzbrq3sftYNs3Ys9w+2 OFhLNoGRHk2ze3Tt1LwVzFNH07bQvqcOafd8wPmTcnPDEqLY90B7iW8CT1aRaeYcmQ1e SQEUYkrRoGsJhtcE7idmY+jSycptCBikIupWFdM1blmgc1pCQpM9M5rbXqkEEPcz4oGk o6j6IGMmcowMosS96jnq0Sxw5PN0Wd2Pw03MC8LWTBtBZv9rnVMh+b3RFbvHmyH+uM6H YHBw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1721433069; x=1722037869; 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=nQJLhJt+1v3X0AxqN/F0tmRwTbToicxjNz2Hd7wYOIk=; b=cL5ps2T9eKFA7uTVSFutacLb0GOTc1SePebQrSnWHaUzzValW9QuuY+ZjaNCW6aWlb sXNdkIAM6KeYsNepylC7exJDduVfHLWabFly8zPzT2LLo2EalRhtDTchcK2DbqNVNe2q xAtgabTftnV3goe7grReQtDrH5KD/4Fdk9J5zyMgf+3v+ZY3/P/2WNH+MoyUYEWg6gHa CwuApwW90IsrU9UBPiBI72kWKJQ6m6BUMdcBTzrjtSCsCnWrwWSDRxgGCJjfnl8BSU1A /jRwoNp1HDXESDqnpRJbfGZxkiw1valMWMHcwjb2mk4QNyO93jfueGj+Q+VP9o6vePpm kz/Q== X-Gm-Message-State: AOJu0YyxZF5eca7DenYGDz7w/KPlbDQvdqlfln9JAAYMBfgJGKyDbUHV Q2gp0Iy8xQJZXAL5GZLj+GKWUzRbD2H0j89+HyJg/UmKcL8Z+WjhB3mILuzRrvciDw+EEgewlix HXQ== X-Google-Smtp-Source: AGHT+IHA4uFOX6R8gDEoOdxVxC3aj3ohqbTJdG43loopxhosAVlg2my7BLXNDlYk3WWyGS51f3CGp+OjeTc= X-Received: from zagreus.c.googlers.com ([fda3:e722:ac3:cc00:7f:e700:c0a8:5c37]) (user=seanjc job=sendgmr) by 2002:a63:dc54:0:b0:719:8067:6bca with SMTP id 41be03b00d2f7-79f9d72bcb9mr2878a12.1.1721433069304; Fri, 19 Jul 2024 16:51:09 -0700 (PDT) Reply-To: Sean Christopherson Date: Fri, 19 Jul 2024 16:50:57 -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 2.45.2.1089.g2a221341d9-goog Message-ID: <20240719235107.3023592-1-seanjc@google.com> Subject: [PATCH v2 00/10] KVM: x86: Fix ICR handling when x2AVIC is active From: Sean Christopherson To: Sean Christopherson , Paolo Bonzini Cc: kvm@vger.kernel.org, linux-kernel@vger.kernel.org, Maxim Levitsky , Suravee Suthikulpanit I made the mistake of expanding my testing to run with and without AVIC enabled, and to my surprise (wow, sarcasm), x2AVIC failed hard on the xapic_state_test due to ICR issues. AFAICT, the issue is that AMD splits the 64-bit ICR into the legacy ICR and ICR2 fields when storing the ICR in the vAPIC (apparently "it's a single 64-bit register" is open to intepretation). Aside from causing the selftest failure and potential live migration issues, botching the format is quite bad, as KVM will mishandle incomplete virtualized IPIs, e.g. generate IRQs to the wrong vCPU, drop IRQs, etc. Patch 1 fixes are rather annoying wart where the xapic_state *deliberately* skips reserved bit tests to work around a KVM bug. *sigh* I couldn't find anything definitive in the APM, my findings are based on testing on Genoa. v2: Actually send the whole series. Sean Christopherson (10): KVM: x86: Enforce x2APIC's must-be-zero reserved ICR bits KVM: x86: Move x2APIC ICR helper above kvm_apic_write_nodecode() KVM: x86: Re-split x2APIC ICR into ICR+ICR2 for AMD (x2AVIC) KVM: selftests: Open code vcpu_run() equivalent in guest_printf test KVM: selftests: Report unhandled exceptions on x86 as regular guest asserts KVM: selftests: Add x86 helpers to play nice with x2APIC MSR #GPs KVM: selftests: Skip ICR.BUSY test in xapic_state_test if x2APIC is enabled KVM: selftests: Test x2APIC ICR reserved bits KVM: selftests: Verify the guest can read back the x2APIC ICR it wrote KVM: selftests: Play nice with AMD's AVIC errata arch/x86/include/asm/kvm_host.h | 2 + arch/x86/kvm/lapic.c | 73 +++++++++++++------ arch/x86/kvm/svm/svm.c | 2 + arch/x86/kvm/vmx/main.c | 2 + .../testing/selftests/kvm/guest_print_test.c | 19 ++++- .../selftests/kvm/include/x86_64/apic.h | 21 +++++- .../selftests/kvm/lib/x86_64/processor.c | 8 +- .../selftests/kvm/x86_64/xapic_state_test.c | 54 +++++++++----- 8 files changed, 135 insertions(+), 46 deletions(-) base-commit: 332d2c1d713e232e163386c35a3ba0c1b90df83f