From nobody Tue Feb 10 06:04:27 2026 Received: from smtp-out2.suse.de (smtp-out2.suse.de [195.135.223.131]) (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 383ED2512FF for ; Sun, 8 Feb 2026 16:43:04 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=195.135.223.131 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1770568984; cv=none; b=CkAnYRipghWjIHWeTNQzHIDILOmveglCM+2i8c71eKjgG5FilIoMZzt87cc/phwUAE14lJAZ4V323YP75fxw8/SIPVDU41/16N2BtWpExMS0mOyVx7pmApPKVLWiUpJ9ihusLm3W6PnMGqPXRM77HAZDotXMPur37vg5G1vV9PQ= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1770568984; c=relaxed/simple; bh=7ga8ey+S+WsI7rjbEMDElhxozP0ToevHzdbgEl8wCBY=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version:Content-Type; b=Jb3iXE0g87PqFRQKG7mcUWRYBc0EO1jM5bryzhHbduY7SB/93orMPXewOu/2VNbwvh3FT4PF4JiuJov0GSfS9cRg6OFmqloKGwK1euvYp5FT4fmytda18fkz2HqQQajehGYeqwtEwXRZJvPQf2QErF1B4V4MM/e5VGP10zHuP2E= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=suse.de; spf=pass smtp.mailfrom=suse.de; dkim=pass (1024-bit key) header.d=suse.de header.i=@suse.de header.b=dQ3PEOXB; dkim=permerror (0-bit key) header.d=suse.de header.i=@suse.de header.b=+mBy3lA1; dkim=pass (1024-bit key) header.d=suse.de header.i=@suse.de header.b=dQ3PEOXB; dkim=permerror (0-bit key) header.d=suse.de header.i=@suse.de header.b=+mBy3lA1; arc=none smtp.client-ip=195.135.223.131 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=suse.de Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=suse.de Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=suse.de header.i=@suse.de header.b="dQ3PEOXB"; dkim=permerror (0-bit key) header.d=suse.de header.i=@suse.de header.b="+mBy3lA1"; dkim=pass (1024-bit key) header.d=suse.de header.i=@suse.de header.b="dQ3PEOXB"; dkim=permerror (0-bit key) header.d=suse.de header.i=@suse.de header.b="+mBy3lA1" Received: from imap1.dmz-prg2.suse.org (imap1.dmz-prg2.suse.org [IPv6:2a07:de40:b281:104:10:150:64:97]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (No client certificate requested) by smtp-out2.suse.de (Postfix) with ESMTPS id 5E4735BCDF; Sun, 8 Feb 2026 16:43:02 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.de; s=susede2_rsa; t=1770568982; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding; bh=dPteStqC1EGaXLVEirmdOkrStpftmhePwOCUjlCU5is=; b=dQ3PEOXBY9G9qHDMi/6RrupOy+IDIK0RuEJ6RR+hii4pfgFVSOV5WtQmteHkT0NmXFpzaq 2rO5gqHkjfHKrbI5x64GPd0VtwS956xvJx3pk5hnfCZiCNdcJwffqTs+9PeU8Pxo81/wHh 5VHUeJhpEgSb4pvK5cweI1Opf6TmEFk= DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=suse.de; s=susede2_ed25519; t=1770568982; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding; bh=dPteStqC1EGaXLVEirmdOkrStpftmhePwOCUjlCU5is=; b=+mBy3lA1mOmpnybt2oA1Dl8P2J4he0dr6DEyz0vtmat5bzndwaRUCVbue0RTempUFV1+te G1QV4x7OZFZLlfDQ== Authentication-Results: smtp-out2.suse.de; dkim=pass header.d=suse.de header.s=susede2_rsa header.b=dQ3PEOXB; dkim=pass header.d=suse.de header.s=susede2_ed25519 header.b=+mBy3lA1 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.de; s=susede2_rsa; t=1770568982; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding; bh=dPteStqC1EGaXLVEirmdOkrStpftmhePwOCUjlCU5is=; b=dQ3PEOXBY9G9qHDMi/6RrupOy+IDIK0RuEJ6RR+hii4pfgFVSOV5WtQmteHkT0NmXFpzaq 2rO5gqHkjfHKrbI5x64GPd0VtwS956xvJx3pk5hnfCZiCNdcJwffqTs+9PeU8Pxo81/wHh 5VHUeJhpEgSb4pvK5cweI1Opf6TmEFk= DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=suse.de; s=susede2_ed25519; t=1770568982; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding; bh=dPteStqC1EGaXLVEirmdOkrStpftmhePwOCUjlCU5is=; b=+mBy3lA1mOmpnybt2oA1Dl8P2J4he0dr6DEyz0vtmat5bzndwaRUCVbue0RTempUFV1+te G1QV4x7OZFZLlfDQ== Received: from imap1.dmz-prg2.suse.org (localhost [127.0.0.1]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (No client certificate requested) by imap1.dmz-prg2.suse.org (Postfix) with ESMTPS id ABE723EA63; Sun, 8 Feb 2026 16:43:01 +0000 (UTC) Received: from dovecot-director2.suse.de ([2a07:de40:b281:106:10:150:64:167]) by imap1.dmz-prg2.suse.org with ESMTPSA id Af3kJRW9iGm9DQAAD6G6ig (envelope-from ); Sun, 08 Feb 2026 16:43:01 +0000 From: =?UTF-8?q?Carlos=20L=C3=B3pez?= To: seanjc@google.com, bp@alien8.de, kvm@vger.kernel.org Cc: =?UTF-8?q?Carlos=20L=C3=B3pez?= , Paolo Bonzini , Thomas Gleixner , Ingo Molnar , Dave Hansen , x86@kernel.org (maintainer:X86 ARCHITECTURE (32-BIT AND 64-BIT)), "H. Peter Anvin" , linux-kernel@vger.kernel.org (open list:X86 ARCHITECTURE (32-BIT AND 64-BIT)) Subject: [PATCH] KVM: x86: synthesize TSA CPUID bits via SCATTERED_F() Date: Sun, 8 Feb 2026 17:42:33 +0100 Message-ID: <20260208164233.30405-1-clopez@suse.de> X-Mailer: git-send-email 2.51.0 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable X-Spam-Score: -3.51 X-Spamd-Result: default: False [-3.51 / 50.00]; BAYES_HAM(-3.00)[100.00%]; MID_CONTAINS_FROM(1.00)[]; NEURAL_HAM_LONG(-1.00)[-1.000]; R_DKIM_ALLOW(-0.20)[suse.de:s=susede2_rsa,suse.de:s=susede2_ed25519]; NEURAL_HAM_SHORT(-0.20)[-1.000]; MIME_GOOD(-0.10)[text/plain]; MX_GOOD(-0.01)[]; RCVD_VIA_SMTP_AUTH(0.00)[]; ARC_NA(0.00)[]; FUZZY_RATELIMITED(0.00)[rspamd.com]; MIME_TRACE(0.00)[0:+]; RCPT_COUNT_SEVEN(0.00)[8]; RCVD_TLS_ALL(0.00)[]; TO_DN_SOME(0.00)[]; FROM_EQ_ENVFROM(0.00)[]; FROM_HAS_DN(0.00)[]; DNSWL_BLOCKED(0.00)[2a07:de40:b281:106:10:150:64:167:received,2a07:de40:b281:104:10:150:64:97:from]; RCVD_COUNT_TWO(0.00)[2]; TO_MATCH_ENVRCPT_ALL(0.00)[]; DBL_BLOCKED_OPENRESOLVER(0.00)[suse.de:dkim,suse.de:mid,suse.de:email]; DKIM_SIGNED(0.00)[suse.de:s=susede2_rsa,suse.de:s=susede2_ed25519]; DKIM_TRACE(0.00)[suse.de:+] X-Spam-Level: X-Rspamd-Action: no action X-Rspamd-Queue-Id: 5E4735BCDF X-Rspamd-Server: rspamd1.dmz-prg2.suse.org X-Spam-Flag: NO KVM incorrectly synthesizes TSA_SQ_NO and TSA_L1_NO when running on AMD Family 19h CPUs by using SYNTHESIZED_F(), which unconditionally enables features for KVM-only CPUID leaves (as is the case with CPUID_8000_0021_ECX), regardless of the kernel's synthesis logic in tsa_init(). This is due to the following logic in kvm_cpu_cap_init(): if (leaf < NCAPINTS) kvm_cpu_caps[leaf] &=3D kernel_cpu_caps[leaf]; This can cause an unexpected failure on Family 19h CPUs during SEV-SNP guest setup, when userspace issues SNP_LAUNCH_UPDATE, as setting these bits in the CPUID page on vulnerable CPUs is explicitly rejected by SNP firmware. Switch to SCATTERED_F(), so that the bits are only set if the features have been force-set by the kernel in tsa_init(), or if they are reported in the raw CPUID. Fixes: 31272abd5974 ("KVM: SVM: Advertise TSA CPUID bits to guests") Signed-off-by: Carlos L=C3=B3pez Reviewed-by: Jim Mattson --- arch/x86/kvm/cpuid.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/arch/x86/kvm/cpuid.c b/arch/x86/kvm/cpuid.c index 88a5426674a1..819c176e02ff 100644 --- a/arch/x86/kvm/cpuid.c +++ b/arch/x86/kvm/cpuid.c @@ -1230,8 +1230,8 @@ void kvm_set_cpu_caps(void) ); =20 kvm_cpu_cap_init(CPUID_8000_0021_ECX, - SYNTHESIZED_F(TSA_SQ_NO), - SYNTHESIZED_F(TSA_L1_NO), + SCATTERED_F(TSA_SQ_NO), + SCATTERED_F(TSA_L1_NO), ); =20 kvm_cpu_cap_init(CPUID_8000_0022_EAX, base-commit: 0de4a0eec25b9171f2a2abb1a820e125e6797770 --=20 2.51.0