From patchwork Mon Nov 11 11:59:46 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Peter Zijlstra X-Patchwork-Id: 13870712 Received: from desiato.infradead.org (desiato.infradead.org [90.155.92.199]) (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 909D01850AF; Mon, 11 Nov 2024 12:54:36 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=90.155.92.199 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1731329678; cv=none; b=bcm2TtidgbHk5Ern4qDBLvpWhgQ+/Bsr1hFw+FCVCXFkpuIuTIUZ4NlT6WK3DxPyG2OgLWn2duML+CHWxojs/wSenAwUhi0Cae6gA4ZBJdru3I2hv6DoyzcxDsXT9OVu/c2VwY52Vg/j2bPKDN+RYgI8hwXNbc4TRXfmqhmcD4o= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1731329678; c=relaxed/simple; bh=njWlbghBF0JH2VFA38VkKHvuHFbC5tXgU00ibS8oZCU=; h=Message-Id:Date:From:To:Cc:Subject:References:MIME-Version: Content-Type; b=H2EuOebJwqfrgbwB1mAIjsg1IAe6T++RA0o2TyMou4dDpPqBYvfnWn941jR19FBEb75TyMxSA6cW4M8X/tigWVOWh6/rt2YTYNE5oRxo5gRwBeMqNhle8qYRRrGDC/aHV52du0xqn2m8sHsXFmh3xsgOMLy47yp15ui7czoLfIs= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=infradead.org; spf=none smtp.mailfrom=infradead.org; dkim=pass (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b=HWkCkwGw; arc=none smtp.client-ip=90.155.92.199 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=infradead.org Authentication-Results: smtp.subspace.kernel.org; spf=none smtp.mailfrom=infradead.org Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="HWkCkwGw" DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=desiato.20200630; h=Content-Type:MIME-Version:References: Subject:Cc:To:From:Date:Message-Id:Sender:Reply-To:Content-Transfer-Encoding: Content-ID:Content-Description:In-Reply-To; bh=VD8wRttp+FatX9b+/O+oQABiC0DBtKQAPEWfVxMeFu0=; b=HWkCkwGwu54kQmqDRRp5thWhRy q/Cg0HbirAnYelPnYcOMQ7J4qfUpaRLqVAEPP55JHrFi63/arieiI0UUx8NS//qxe4fwFLOEefZX3 POv2oUk7HT7mp38LoXXiZFyJdHMoBdsi6b8t3iSnBzBvIethWw1VxSdY6AN3UjJOpokR4XzjzzrVS yp+B/oxlvvzNorpb0/VPCGL5PGf3vh/WzTZWeB+zpjMeas1i2GxQeI2sT7ZP8d13CIZqYPs1oT8lX EpUWofcELOTEgLn3GmMNcbyyL4if2ysXyiXqRjzMFPPZwW0jPyQU+gzPhJ93BY/a899OxzwmoT1DF DB8wySfw==; Received: from j130084.upc-j.chello.nl ([24.132.130.84] helo=noisy.programming.kicks-ass.net) by desiato.infradead.org with esmtpsa (Exim 4.98 #2 (Red Hat Linux)) id 1tATwA-0000000Cqjp-1yP1; Mon, 11 Nov 2024 12:54:34 +0000 Received: by noisy.programming.kicks-ass.net (Postfix, from userid 0) id ED37930221D; Mon, 11 Nov 2024 13:54:32 +0100 (CET) Message-Id: <20241111125219.248649120@infradead.org> User-Agent: quilt/0.65 Date: Mon, 11 Nov 2024 12:59:46 +0100 From: Peter Zijlstra To: seanjc@google.com, pbonzini@redhat.com, jpoimboe@redhat.com, tglx@linutronix.de Cc: linux-kernel@vger.kernel.org, x86@kernel.org, kvm@vger.kernel.org, jthoughton@google.com, "Peter Zijlstra (Intel)" Subject: [PATCH v2 11/12] x86/kvm/emulate: Implement test_cc() in C References: <20241111115935.796797988@infradead.org> Precedence: bulk X-Mailing-List: kvm@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Current test_cc() uses the fastop infrastructure to test flags using SETcc instructions. However, int3_emulate_jcc() already fully implements the flags->CC mapping, use that. Removes a pile of gnarly asm. Signed-off-by: Peter Zijlstra (Intel) Acked-by: Sean Christopherson --- arch/x86/include/asm/text-patching.h | 20 +++++++++++++------- arch/x86/kvm/emulate.c | 34 ++-------------------------------- 2 files changed, 15 insertions(+), 39 deletions(-) --- a/arch/x86/include/asm/text-patching.h +++ b/arch/x86/include/asm/text-patching.h @@ -176,9 +176,9 @@ void int3_emulate_ret(struct pt_regs *re } static __always_inline -void int3_emulate_jcc(struct pt_regs *regs, u8 cc, unsigned long ip, unsigned long disp) +bool __emulate_cc(unsigned long flags, u8 cc) { - static const unsigned long jcc_mask[6] = { + static const unsigned long cc_mask[6] = { [0] = X86_EFLAGS_OF, [1] = X86_EFLAGS_CF, [2] = X86_EFLAGS_ZF, @@ -191,15 +191,21 @@ void int3_emulate_jcc(struct pt_regs *re bool match; if (cc < 0xc) { - match = regs->flags & jcc_mask[cc >> 1]; + match = flags & cc_mask[cc >> 1]; } else { - match = ((regs->flags & X86_EFLAGS_SF) >> X86_EFLAGS_SF_BIT) ^ - ((regs->flags & X86_EFLAGS_OF) >> X86_EFLAGS_OF_BIT); + match = ((flags & X86_EFLAGS_SF) >> X86_EFLAGS_SF_BIT) ^ + ((flags & X86_EFLAGS_OF) >> X86_EFLAGS_OF_BIT); if (cc >= 0xe) - match = match || (regs->flags & X86_EFLAGS_ZF); + match = match || (flags & X86_EFLAGS_ZF); } - if ((match && !invert) || (!match && invert)) + return (match && !invert) || (!match && invert); +} + +static __always_inline +void int3_emulate_jcc(struct pt_regs *regs, u8 cc, unsigned long ip, unsigned long disp) +{ + if (__emulate_cc(regs->flags, cc)) ip += disp; int3_emulate_jmp(regs, ip); --- a/arch/x86/kvm/emulate.c +++ b/arch/x86/kvm/emulate.c @@ -26,6 +26,7 @@ #include #include #include +#include #include "x86.h" #include "tss.h" @@ -416,31 +417,6 @@ static int fastop(struct x86_emulate_ctx ON64(FOP3E(op##q, rax, rdx, cl)) \ FOP_END -/* Special case for SETcc - 1 instruction per cc */ -#define FOP_SETCC(op) \ - FOP_FUNC(op) \ - #op " %al \n\t" \ - FOP_RET(op) - -FOP_START(setcc) -FOP_SETCC(seto) -FOP_SETCC(setno) -FOP_SETCC(setc) -FOP_SETCC(setnc) -FOP_SETCC(setz) -FOP_SETCC(setnz) -FOP_SETCC(setbe) -FOP_SETCC(setnbe) -FOP_SETCC(sets) -FOP_SETCC(setns) -FOP_SETCC(setp) -FOP_SETCC(setnp) -FOP_SETCC(setl) -FOP_SETCC(setnl) -FOP_SETCC(setle) -FOP_SETCC(setnle) -FOP_END; - FOP_START(salc) FOP_FUNC(salc) "pushf; sbb %al, %al; popf \n\t" @@ -1064,13 +1040,7 @@ static int em_bsr_c(struct x86_emulate_c static __always_inline u8 test_cc(unsigned int condition, unsigned long flags) { - u8 rc; - void (*fop)(void) = (void *)em_setcc + FASTOP_SIZE * (condition & 0xf); - - flags = (flags & EFLAGS_MASK) | X86_EFLAGS_IF; - asm("push %[flags]; popf; " CALL_NOSPEC - : "=a"(rc), ASM_CALL_CONSTRAINT : [thunk_target]"r"(fop), [flags]"r"(flags)); - return rc; + return __emulate_cc(flags, condition & 0xf); } static void fetch_register_operand(struct operand *op)