From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mgamail.intel.com (mgamail.intel.com [192.198.163.8]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 6EBB13C9429; Wed, 29 Jul 2026 19:43:41 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=192.198.163.8 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1785354228; cv=none; b=OCGLw/TAe7BsrAvrej855dtJ/A9xutUoiJ0P6YKbQG6VMLM4XDob6S+cb0fK5If/a2SJ9gg4I9J1xKk8hReT7rEFkLoePFa8apCvs/MbIxjTPRWyvj3K2BtNYiLHf3lSv0/U+QdC6SSkXr/6+xd1KHKjWIPMT+bTPZOCSCmJN7s= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1785354228; c=relaxed/simple; bh=0GUmgwR1+KzxXTJz6iffTPJCSR7dd2qwxnZp+au4HrE=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=Jt4i063OolbHXZZmWGJsdMGztZy3aZz4hxr5kDRvY7a9Pr97uh8ia6tSDs/SVLZtzuriWZh/FrMbQQFrToTvL2+R3ddIg+P0T3GWXgHmo1mWUBh83WUmeMnI4Y6fut4dB8HC7fnLab+89it2r5qNfhWbON2BxQji7pQNefnqsnk= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=intel.com; spf=pass smtp.mailfrom=intel.com; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b=h1bz2oSP; arc=none smtp.client-ip=192.198.163.8 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=intel.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=intel.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b="h1bz2oSP" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1785354223; x=1816890223; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=0GUmgwR1+KzxXTJz6iffTPJCSR7dd2qwxnZp+au4HrE=; b=h1bz2oSPUxHIaKPj2ECnpeyTcUWVflJBLCFhORgSxOsu/69gV8IkQoBn CqrjyMQMOj/XrOyFLR72hm7VIzcyP6CnpCMYvqIQx+U4KT1dCZqaQiDAJ 6mAft2y+RYlZLr+J2aO+Y1vP1is5Ymgz1yC2juFbLrYNG/dkDjBKn4qIT IGq5irvtVYPsc93BGwhFYWuxzIwnd1coPa/OGZt8dXq9him5b1L4+tS13 NTeY0m0KQ9NqcSnhhLt4XMcr2K1klom1uhCjrj3MlipC+dZSHpv0DmWE9 VDsRrZnyjnQJtZx6lQcm5cW2B2pHCmvYxJ/mO9rbzuD5VfM/FnAjnjNyp w==; X-CSE-ConnectionGUID: b0BpSGfyTqm71oiXzAkD6A== X-CSE-MsgGUID: 1ASIhTldQFSazTgPyO2f5A== X-IronPort-AV: E=McAfee;i="6800,10657,11859"; a="103508280" X-IronPort-AV: E=Sophos;i="6.25,193,1779174000"; d="scan'208";a="103508280" Received: from fmviesa007.fm.intel.com ([10.60.135.147]) by fmvoesa102.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 29 Jul 2026 12:43:26 -0700 X-CSE-ConnectionGUID: xqJtT46YRyiWPZS9aDEmtg== X-CSE-MsgGUID: UI0Q0zJlSxmelKjYJnhpZQ== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.25,193,1779174000"; d="scan'208";a="256769251" Received: from chang-linux-3.sc.intel.com (HELO chang-linux-3) ([172.25.66.174]) by fmviesa007.fm.intel.com with ESMTP; 29 Jul 2026 12:43:26 -0700 From: "Chang S. Bae" To: pbonzini@redhat.com, seanjc@google.com Cc: kvm@vger.kernel.org, x86@kernel.org, linux-kernel@vger.kernel.org, chang.seok.bae@intel.com Subject: [PATCH v6 10/20] KVM: x86: Support EGPR accessing and tracking for emulator Date: Wed, 29 Jul 2026 19:16:46 +0000 Message-ID: <20260729191656.598771-11-chang.seok.bae@intel.com> X-Mailer: git-send-email 2.51.0 In-Reply-To: <20260729191656.598771-1-chang.seok.bae@intel.com> References: <20260729191656.598771-1-chang.seok.bae@intel.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Extend the emulator context and GPR accessors to handle EGPRs before adding support for REX2-prefixed instructions. Like VCPU cache, the emulator can uniformly cache and track all GPRs. Also replace `1 << reg` with `BIT(reg)` in reg_read()/reg_write(). The former performs a signed 32-bit shift, which becomes undefined for R31. BIT() instead shifts an unsigned value that is suitable for all indices. Signed-off-by: Chang S. Bae --- V4 -> V5: Fix possible shift-out-of-bounds (review bot [*]) [*]: locally running Sashiko with gemini-3.1-pro-preview --- arch/x86/kvm/kvm_emulate.h | 20 +++++++++++--------- 1 file changed, 11 insertions(+), 9 deletions(-) diff --git a/arch/x86/kvm/kvm_emulate.h b/arch/x86/kvm/kvm_emulate.h index 3e375af15c03..b1498f618c81 100644 --- a/arch/x86/kvm/kvm_emulate.h +++ b/arch/x86/kvm/kvm_emulate.h @@ -109,13 +109,13 @@ struct x86_instruction_info { struct x86_emulate_ops { void (*vm_bugged)(struct x86_emulate_ctxt *ctxt); /* - * read_gpr: read a general purpose register (rax - r15) + * read_gpr: read a general purpose register (rax - r31) * * @reg: gpr number. */ ulong (*read_gpr)(struct x86_emulate_ctxt *ctxt, unsigned reg); /* - * write_gpr: write a general purpose register (rax - r15) + * write_gpr: write a general purpose register (rax - r31) * * @reg: gpr number. * @val: value to write. @@ -321,7 +321,9 @@ typedef void (*fastop_t)(struct fastop *); * also uses _eip, RIP cannot be a register operand nor can it be an operand in * a ModRM or SIB byte. */ -#ifdef CONFIG_X86_64 +#if defined(CONFIG_KVM_APX) +#define NR_EMULATOR_GPRS 32 +#elif defined(CONFIG_X86_64) #define NR_EMULATOR_GPRS 16 #else #define NR_EMULATOR_GPRS 8 @@ -381,9 +383,9 @@ struct x86_emulate_ctxt { u8 lock_prefix; u8 rep_prefix; /* bitmaps of registers in _regs[] that can be read */ - u16 regs_valid; + u32 regs_valid; /* bitmaps of registers in _regs[] that have been written */ - u16 regs_dirty; + u32 regs_dirty; /* modrm */ u8 modrm; u8 modrm_mod; @@ -547,8 +549,8 @@ static inline ulong reg_read(struct x86_emulate_ctxt *ctxt, unsigned nr) if (KVM_EMULATOR_BUG_ON(nr >= NR_EMULATOR_GPRS, ctxt)) nr &= NR_EMULATOR_GPRS - 1; - if (!(ctxt->regs_valid & (1 << nr))) { - ctxt->regs_valid |= 1 << nr; + if (!(ctxt->regs_valid & BIT(nr))) { + ctxt->regs_valid |= BIT(nr); ctxt->_regs[nr] = ctxt->ops->read_gpr(ctxt, nr); } return ctxt->_regs[nr]; @@ -562,8 +564,8 @@ static inline ulong *reg_write(struct x86_emulate_ctxt *ctxt, unsigned nr) BUILD_BUG_ON(sizeof(ctxt->regs_dirty) * BITS_PER_BYTE < NR_EMULATOR_GPRS); BUILD_BUG_ON(sizeof(ctxt->regs_valid) * BITS_PER_BYTE < NR_EMULATOR_GPRS); - ctxt->regs_valid |= 1 << nr; - ctxt->regs_dirty |= 1 << nr; + ctxt->regs_valid |= BIT(nr); + ctxt->regs_dirty |= BIT(nr); return &ctxt->_regs[nr]; } -- 2.53.0