From nobody Thu Oct 2 19:27:56 2025 Received: from mail-pl1-f201.google.com (mail-pl1-f201.google.com [209.85.214.201]) (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 E173B28643F for ; Fri, 12 Sep 2025 23:23:51 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.214.201 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1757719433; cv=none; b=Q1FolFmxxZ028iDMEB3B8IudPZgdtjDwWeHUmfbcEoWvNdC9yWoO0blImqPwjzBNy6X8oGl6Xzd7aAh9GCBIR1mIcagz+cjVGl1yV/deYB18D/t/xFYrlU54UxBqN2WSgPTdSEAvilQM4kOAN7MdpnlAX5FScoOD5MQXBIqDJ5M= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1757719433; c=relaxed/simple; bh=JEEiCFkCBP5ttonqiWIsRl8yCbVxEhdAgkHtYSFLdVw=; h=Date:In-Reply-To:Mime-Version:References:Message-ID:Subject:From: To:Cc:Content-Type; b=EP9l911UNxAz+eOouS1DeREgTcTPbDVSS2lbCZi2KHdWjv9R0EMqjydoLpmITxe8klKD2sIoD0otMrJTPVwOylKuqfXRvyJqry/KMql2FGOMlNWprQ5fMFjx72F2TphezcY2habLmkPbgN4mZtes2o3Pioh8X5oNAhpNDAaOwdk= 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=Vwwtle6r; arc=none smtp.client-ip=209.85.214.201 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="Vwwtle6r" Received: by mail-pl1-f201.google.com with SMTP id d9443c01a7336-25c7a4859e0so17757765ad.1 for ; Fri, 12 Sep 2025 16:23:51 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20230601; t=1757719431; x=1758324231; darn=vger.kernel.org; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:reply-to:from:to:cc:subject:date:message-id:reply-to; bh=oNB6mEDZxyaqSYryMY9uR6ecFN+PIMonXdA8ZyarKi0=; b=Vwwtle6rTcDDy/09sHRRtrONQ9ZaaKagG4e/HKwA2TY1kywnzAXad52SNvQ7cyDOhP 5HX+VlHSNJpNe7xIjdrAglbV/w3k/U4ECt141gv1Q8YIzvowxzfPM0oKHrGmtFCIhRsZ l7Dx7PMijQ5gzKq78ZMm+IIFvO8uO7PbYyYbOYf35rJIBusRQ7VQjfHcN7n6g15JGTwK DnkcfGzwoBxJvilU2iBTVtaXppxb8Vmk0yUVNMHh4n7UQVEZ7FR6MBTjuXCQUI1Vg2X8 YoJNMHbyzUCZZya1PVLd5SJc6F8q2TV0qb3QZVJWqsFW3AlOWHgKaTZXCExMvvEILUCf qhzg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1757719431; x=1758324231; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:reply-to:x-gm-message-state:from:to:cc:subject:date:message-id :reply-to; bh=oNB6mEDZxyaqSYryMY9uR6ecFN+PIMonXdA8ZyarKi0=; b=PM1mhcyKv0wmQCTqn/epWTcUkpjdwbxxHXCqWAZJLOgGvGDVjYtkGdTB0rw/V0OV6J nzPTRAbMi4x5prj4jjbY/vR6R/QK3hiTaKcikens5JTlK5mfx0jFa8/evZoDfdkVcShA wyipX0GKNTUV8QBpLGcyTcm3vrMPYv2niWzvayLbqAVOH+jQ2CU8EcDFmuUEfpx1YNzq GME39DfSM8snJgiAfUVsgnWZ536eibV0HjPFwtIn2nCugnwm1UQywKpc9a4/gy9f8XwX SRGOcvW8fZe6JaPBlPDgZssUSVAqKbMv+SGEtr2ELNXSQLhQJxDWlEaNh4Uk+++TtDPU swGw== X-Forwarded-Encrypted: i=1; AJvYcCXDeGdRofM8K1A29e+8q6CqKWXiJJzTcTjatzQA3njQb5dQ7hM0fLEf7e9ryMZoAtKkGasRo0J9Qrtmsvg=@vger.kernel.org X-Gm-Message-State: AOJu0YxisQ8vwVP0uVaBwYdWfuzWBoIRAcyliYzlYzvguC8HThuVgxhX ZNfiU+WCQebSEc9HlNQGTDKTPd7NRMoCa2gm7jsM7lP1lJfk6JekLuURf25MUJzWyeyCc1/xs0B wjSQLNA== X-Google-Smtp-Source: AGHT+IGS+NoAkSIvkgqHUng4iiyhhkD7f5OcKeKYit5O8WCfjDkLzEvEzCprS1GK1c6HC/ZzIm4cvgzzR3k= X-Received: from pjzz6.prod.google.com ([2002:a17:90b:58e6:b0:327:e172:e96]) (user=seanjc job=prod-delivery.src-stubby-dispatcher) by 2002:a17:903:22c3:b0:24c:ea1c:1156 with SMTP id d9443c01a7336-25bae1218abmr92927335ad.24.1757719431283; Fri, 12 Sep 2025 16:23:51 -0700 (PDT) Reply-To: Sean Christopherson Date: Fri, 12 Sep 2025 16:22:53 -0700 In-Reply-To: <20250912232319.429659-1-seanjc@google.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 References: <20250912232319.429659-1-seanjc@google.com> X-Mailer: git-send-email 2.51.0.384.g4c02a37b29-goog Message-ID: <20250912232319.429659-16-seanjc@google.com> Subject: [PATCH v15 15/41] KVM: x86: Save and reload SSP to/from SMRAM From: Sean Christopherson To: Paolo Bonzini , Sean Christopherson Cc: kvm@vger.kernel.org, linux-kernel@vger.kernel.org, Tom Lendacky , Mathias Krause , John Allen , Rick Edgecombe , Chao Gao , Maxim Levitsky , Xiaoyao Li , Zhang Yi Z Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" From: Yang Weijiang Save CET SSP to SMRAM on SMI and reload it on RSM. KVM emulates HW arch behavior when guest enters/leaves SMM mode,i.e., save registers to SMRAM at the entry of SMM and reload them at the exit to SMM. Per SDM, SSP is one of such registers on 64-bit Arch, and add the support for SSP. Suggested-by: Sean Christopherson Signed-off-by: Yang Weijiang Tested-by: Mathias Krause Tested-by: John Allen Tested-by: Rick Edgecombe Signed-off-by: Chao Gao Signed-off-by: Sean Christopherson Reviewed-by: Binbin Wu Reviewed-by: Xiaoyao Li --- arch/x86/kvm/smm.c | 8 ++++++++ arch/x86/kvm/smm.h | 2 +- 2 files changed, 9 insertions(+), 1 deletion(-) diff --git a/arch/x86/kvm/smm.c b/arch/x86/kvm/smm.c index 5dd8a1646800..b0b14ba37f9a 100644 --- a/arch/x86/kvm/smm.c +++ b/arch/x86/kvm/smm.c @@ -269,6 +269,10 @@ static void enter_smm_save_state_64(struct kvm_vcpu *v= cpu, enter_smm_save_seg_64(vcpu, &smram->gs, VCPU_SREG_GS); =20 smram->int_shadow =3D kvm_x86_call(get_interrupt_shadow)(vcpu); + + if (guest_cpu_cap_has(vcpu, X86_FEATURE_SHSTK) && + kvm_msr_read(vcpu, MSR_KVM_INTERNAL_GUEST_SSP, &smram->ssp)) + kvm_make_request(KVM_REQ_TRIPLE_FAULT, vcpu); } #endif =20 @@ -558,6 +562,10 @@ static int rsm_load_state_64(struct x86_emulate_ctxt *= ctxt, kvm_x86_call(set_interrupt_shadow)(vcpu, 0); ctxt->interruptibility =3D (u8)smstate->int_shadow; =20 + if (guest_cpu_cap_has(vcpu, X86_FEATURE_SHSTK) && + kvm_msr_write(vcpu, MSR_KVM_INTERNAL_GUEST_SSP, smstate->ssp)) + return X86EMUL_UNHANDLEABLE; + return X86EMUL_CONTINUE; } #endif diff --git a/arch/x86/kvm/smm.h b/arch/x86/kvm/smm.h index 551703fbe200..db3c88f16138 100644 --- a/arch/x86/kvm/smm.h +++ b/arch/x86/kvm/smm.h @@ -116,8 +116,8 @@ struct kvm_smram_state_64 { u32 smbase; u32 reserved4[5]; =20 - /* ssp and svm_* fields below are not implemented by KVM */ u64 ssp; + /* svm_* fields below are not implemented by KVM */ u64 svm_guest_pat; u64 svm_host_efer; u64 svm_host_cr4; --=20 2.51.0.384.g4c02a37b29-goog