From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-pl1-f202.google.com (mail-pl1-f202.google.com [209.85.214.202]) (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 756B21865EE for ; Mon, 30 Sep 2024 21:56:52 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.214.202 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1727733413; cv=none; b=uxKWuf7XXZ2VCLTvrEv/mk0ErStaclaM+XmYBmwHPd1Qrk3MGXDU151qShXRK9GJEYOPnijjz1m69K4azGwDaUED3HrafEMfCjFePMWpMESSQf2j6zFjt+RP1GQag4C5XqGkzLHdoW9QmogtCd8pPC+uWGte/UyHGkRjMLuya5k= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1727733413; c=relaxed/simple; bh=EI35CoEM1AcSciWaRt5Y7P85pwkoV/1G1OSkpZxfbPg=; h=Date:In-Reply-To:Mime-Version:References:Message-ID:Subject:From: To:Content-Type; b=YMYMQgxg3flmyzZ+ZGmnOTjTFiCxe1R2fEothVfz28wTkLUl4JSeu7YrYdbz6Qe74Mbu6qs7cmVYknSmNh8TDuKnzDkDtvr4psh8pJr582qHfr/WXXYbiGu1ToZCAGhz1+Z0lIj57MW7HHeyZ3yq/xwH4bnwrbdg/YOAbcTmFX8= 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=iK4ctBoL; arc=none smtp.client-ip=209.85.214.202 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="iK4ctBoL" Received: by mail-pl1-f202.google.com with SMTP id d9443c01a7336-204e310e050so57110745ad.0 for ; Mon, 30 Sep 2024 14:56:52 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20230601; t=1727733412; x=1728338212; darn=vger.kernel.org; h=to:from:subject:message-id:references:mime-version:in-reply-to:date :from:to:cc:subject:date:message-id:reply-to; bh=PntPBodbq4krAqAL/kXN8N5SHx+RiWW9dX81Z4mrKcI=; b=iK4ctBoLbfEykS27Sxro0hN4zq6Fsa8D/e4qyRX7VhXIyF1n7JXLwfPLtAr+02SsQF asndJZN8oS5fIEiuyL4lY15/Qe8MXx0TKmMJ018v9DK2ltmm900NLN7gCfBtwVdOmFrC ujE9k/eLQpDmP097pL4P31lLCQ/DksXqVjD7cNMQQ92Vwi8Zk66qHCaiv8fxl45/lxry pBreIysoDq4cgfoPZuW7cUeTTOA/i6sy6Zzgcw28bsgQjFA4kTdp8fnHG72jkG24coZv sTJnVOcZ0lUMvMqulPFuiFdzszNgB7RjudMC3dLV3w7Q1ISsB7R3+86/cFTIqjqwapMe nJLA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1727733412; x=1728338212; h=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=PntPBodbq4krAqAL/kXN8N5SHx+RiWW9dX81Z4mrKcI=; b=mFhUOcJneC1Q47jyQflBvxDbl5JiN1mRLGh6PYQK5RdDZhPz8iTxJFm6agKwmjVTLt 0VSrFKcSz2i91TqACsPySEXaM0hqkeKUC9LdZLbOHZjcf1T7xcHBjBo+R5yzpydsok6Y ru9aaP9VLkISkCMSwb8Za7NPlE1iy6DLCdadisScsBVYd0rmf404kGro1ybfMbXtkMqd Zpn3SRuCdp1Wm3k+1BWWfrQKG2qsfxgn1as++1c4OcpLwNIvkmZsvIJ8KbiJ1ko2SJtU 8O4MaBFMokF9y+wmZTg96VL60Sra02bOj75hLO+beiUNKVRMxOp+rmRLQQITfaNru5Vj wqaw== X-Forwarded-Encrypted: i=1; AJvYcCWN2nK1+lOpKmc66sw7G/rTJ+QZ+zjz/YKM2TMSu4zperV6tl0BN2q5h2BrYDQQVUcLiYZdSOBB+Moqw0I=@vger.kernel.org X-Gm-Message-State: AOJu0YzNhy3zlfvTJc2+jddxjP2ZXMak2PjDrDVhr8FA4U4e0m+aXzJG S4vQSSsR+Y+TCqVR1fZSRKwYbtH0UsoSlJjV+KJwdIyflnZsqPykVYdgeJBpifJAKfVVIAj9tvd 9lQ== X-Google-Smtp-Source: AGHT+IFa/3NUudFCuE72HcCwi+hM+UVm+5oAl6XGWfqHgohNP2i/0xjhJQmHwp45qjEiLZEOk9HWi9na7w8= X-Received: from zagreus.c.googlers.com ([fda3:e722:ac3:cc00:7f:e700:c0a8:5c37]) (user=seanjc job=sendgmr) by 2002:a17:902:f691:b0:20b:aed1:bf77 with SMTP id d9443c01a7336-20baed1c097mr62225ad.7.1727733411419; Mon, 30 Sep 2024 14:56:51 -0700 (PDT) Date: Mon, 30 Sep 2024 14:56:49 -0700 In-Reply-To: <20240911204158.2034295-4-seanjc@google.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 References: <20240911204158.2034295-1-seanjc@google.com> <20240911204158.2034295-4-seanjc@google.com> Message-ID: Subject: Re: [PATCH v2 03/13] KVM: selftests: Fudge around an apparent gcc bug in arm64's PMU test From: Sean Christopherson To: Marc Zyngier , Oliver Upton , Anup Patel , Paolo Bonzini , Christian Borntraeger , Janosch Frank , Claudio Imbrenda , linux-arm-kernel@lists.infradead.org, kvmarm@lists.linux.dev, kvm@vger.kernel.org, kvm-riscv@lists.infradead.org, linux-riscv@lists.infradead.org, linux-kernel@vger.kernel.org, James Houghton Content-Type: text/plain; charset="us-ascii" On Wed, Sep 11, 2024, Sean Christopherson wrote: > Use u64_replace_bits() instead of u64p_replace_bits() to set PMCR.N in > arm64's vPMU counter access test to fudge around what appears to be a gcc > bug. With the recent change to have vcpu_get_reg() return a value in lieu > of an out-param, some versions of gcc completely ignore the operation > performed by set_pmcr_n(), i.e. ignore the output param. Filed a gcc bug: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=116912 I'll report back if anything interesting comes out of that bug.