From nobody Thu Oct 2 07:46:30 2025 Received: from mail-pj1-f74.google.com (mail-pj1-f74.google.com [209.85.216.74]) (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 96BEB2D660A for ; Fri, 19 Sep 2025 22:33:33 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.216.74 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1758321215; cv=none; b=PKdbKWScEXP8pgJrrdjE3NhJU5puymIxxpEQYakGGexBjeL7EHhJfDYahly3YPID26LmIhqFdPX+MfncMhaxTj5URuLnaccDB34MT2Um2emGGjogxF6+gWg12wWQycT/fJ7l1SLDO+01A4EeGqBIZy87KJujKS8bRMpdojDhSrA= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1758321215; c=relaxed/simple; bh=HEkJNOg3fukhyvlPxWiVIcVFk89Ev4TjVKZ4rbVl6iY=; h=Date:In-Reply-To:Mime-Version:References:Message-ID:Subject:From: To:Cc:Content-Type; b=uqLtSBshF0GU1/W7NAZyYgrr2PbMjrcHfMSAk0s0V9QPju8Jp6d+FAQsyzh5fOHkGUpRodhwJlem8vLmDz/jXxeCwv/3sq5Z7eyhFYvbM0uxPVqb6sSJ+kMlJyKmThb2lybdmohW57Yt+kNX3jl/KQ12zzoAhGVbmOew96Zaz6A= 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=NGUvXG+L; arc=none smtp.client-ip=209.85.216.74 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="NGUvXG+L" Received: by mail-pj1-f74.google.com with SMTP id 98e67ed59e1d1-32e43b0f038so2244419a91.0 for ; Fri, 19 Sep 2025 15:33:33 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20230601; t=1758321213; x=1758926013; 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=SgNuCWJ0Kshu8P8RVZ3w+7X0SuHGq8/X41iuZdsbg84=; b=NGUvXG+Lv6LcxjoOmv5Wzvk2g7OyXOriOC6/IlvB4TwhAHkHvnaCr5QS+muhLZpx01 /Pvn/FsMAjGmbBBCsZrKdurEng4Wf3EhMuO+QnVthKmsZPD7MpmpdtdrttvbqtraKZHR 7H7UvuSrwqBEpmBXlZbC2fuaLthwOWDo78kvoyGkij0uw5AjBwsr4E2bx0/dr4iE8Me3 VPYQy8Q5B2bU2xc2fBOLE4Xt/jPBmvvg1KEG81q83xwSW7ipGjvGzTfCUwhSI9AwUi/p a44PIqutg9/qFov2NnGtiqK8ijTzvyLaxaJGxWuPHWBzvSagGAYT9hEU3PSfMKiUJwt5 ZvQg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1758321213; x=1758926013; 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=SgNuCWJ0Kshu8P8RVZ3w+7X0SuHGq8/X41iuZdsbg84=; b=ggllcg8QYC9rUT/zaNkxLERI9VO68n/Ww54jLdpFFdE+DWWvzUEz08ZHBONDycIp02 oomwEzb/botPo2iaCkUfPYKJaQN7LSqbC1fuwGyO5BpWmOB8xCgDvEwBCqMlfOX45Ws4 1AeUebgCUTUPT1eMEOERiBqSCb9bsRZKiqV+ecf6gOKFC2KLgjtlX1ZcTYRJX1oZcSnj cppibTkA1GZD625RT0/ojbbeFRzUPF72sMd0YJNy8QHvjmLxyGA7QEAgtXqZq+7nldUA Yg3EeZhx2KH/ysIEBqmgzIXFHE4HBYj69YF4qUiQjXN8unjWmBT3BHyXi9zh+JAyVkz8 Pduw== X-Forwarded-Encrypted: i=1; AJvYcCWem26pWJ9pLSxz7koHVPLJSfmUAfDdVqu0zlae6NbVlD5JFZjBoMJfzQvxWNZNjfrVrwQTYIZ5EYDjBrc=@vger.kernel.org X-Gm-Message-State: AOJu0YwCfBFDeFt4pgZNdX6tP+Y6cDqWxGLkMnY4aaW7u6UZZ+nBAa5Y iaWWE7v7oZ1p6x/TeUn+ezQOwiB39ZqznxX1oZ4X8otjKddqjDBiLCkfGIuY29chnU2vmb6C90C 0LIIylA== X-Google-Smtp-Source: AGHT+IFlfcEaDECOLCIYlfDWXjUKejDEVlHyepr/5JJ+6BpQhH93ka0y/qLlXn9wdJM8Rl8KPJ2WMOD9FkY= X-Received: from pjff6.prod.google.com ([2002:a17:90b:5626:b0:329:7dfc:f4e1]) (user=seanjc job=prod-delivery.src-stubby-dispatcher) by 2002:a17:90b:3a8c:b0:32e:d9db:7a86 with SMTP id 98e67ed59e1d1-33097fe0889mr5834323a91.7.1758321213138; Fri, 19 Sep 2025 15:33:33 -0700 (PDT) Reply-To: Sean Christopherson Date: Fri, 19 Sep 2025 15:32:22 -0700 In-Reply-To: <20250919223258.1604852-1-seanjc@google.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 References: <20250919223258.1604852-1-seanjc@google.com> X-Mailer: git-send-email 2.51.0.470.ga7dc726c21-goog Message-ID: <20250919223258.1604852-16-seanjc@google.com> Subject: [PATCH v16 15/51] 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 , Binbin Wu , Xiaoyao Li , Maxim Levitsky , Zhang Yi Z , Xin Li 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 Reviewed-by: Binbin Wu Reviewed-by: Xiaoyao Li Signed-off-by: Sean Christopherson --- 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 2.51.0.470.ga7dc726c21-goog