From patchwork Tue Apr 12 17:32:17 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Varad Gautam X-Patchwork-Id: 12811049 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 8342EC433EF for ; Tue, 12 Apr 2022 17:33:05 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1352207AbiDLRfV (ORCPT ); Tue, 12 Apr 2022 13:35:21 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:43740 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1358290AbiDLRfE (ORCPT ); Tue, 12 Apr 2022 13:35:04 -0400 Received: from smtp-out2.suse.de (smtp-out2.suse.de [195.135.220.29]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 9FF3F62133 for ; Tue, 12 Apr 2022 10:32:28 -0700 (PDT) Received: from imap2.suse-dmz.suse.de (imap2.suse-dmz.suse.de [192.168.254.74]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (P-521) server-digest SHA512) (No client certificate requested) by smtp-out2.suse.de (Postfix) with ESMTPS id 4BFD61F85B; Tue, 12 Apr 2022 17:32:27 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.com; s=susede1; t=1649784747; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=zMgbODgQd4DT4BH60EetBQO7SAUNkwNAdYwqbBoEWQI=; b=rMP3sb2U0+p4uoDxDixhSXqpgHRO1eDHHhya8psoClubruRCgBIUt9K8pGpWjhvQyd6ctk errfBEzaSqE94X+VBv94F3OfklUchGCVMgw/g5P7QC8odow6ndk57CyMbwKLN/G8PJRTh9 tG73U4vbjxyWYLZyITtEP9ENEns23tA= Received: from imap2.suse-dmz.suse.de (imap2.suse-dmz.suse.de [192.168.254.74]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (P-521) server-digest SHA512) (No client certificate requested) by imap2.suse-dmz.suse.de (Postfix) with ESMTPS id B34DE13780; Tue, 12 Apr 2022 17:32:26 +0000 (UTC) Received: from dovecot-director2.suse.de ([192.168.254.65]) by imap2.suse-dmz.suse.de with ESMTPSA id AIl/Kaq3VWJJewAAMHmgww (envelope-from ); Tue, 12 Apr 2022 17:32:26 +0000 From: Varad Gautam To: kvm@vger.kernel.org Cc: pbonzini@redhat.com, drjones@redhat.com, marcorr@google.com, zxwang42@gmail.com, erdemaktas@google.com, rientjes@google.com, seanjc@google.com, brijesh.singh@amd.com, Thomas.Lendacky@amd.com, jroedel@suse.de, bp@suse.de, varad.gautam@suse.com Subject: [PATCH 06/10] x86: efi: Stop using UEFI-provided %gs for percpu storage Date: Tue, 12 Apr 2022 19:32:17 +0200 Message-Id: <20220412173221.13315-6-varad.gautam@suse.com> X-Mailer: git-send-email 2.32.0 In-Reply-To: <20220412173221.13315-1-varad.gautam@suse.com> References: <20220412173221.13315-1-varad.gautam@suse.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org UEFI tests do not update MSR_GS_BASE during bringup, and continue using the GS_BASE set up by the UEFI implementation for percpu storage. Update this MSR during setup_segments64() to allow storing percpu data at a sane location reserved by the testcase, and ensure that this happens before any operation that ends up storing to the percpu space. Signed-off-by: Varad Gautam --- lib/x86/setup.c | 9 ++++++--- x86/efi/efistart64.S | 7 +++++++ 2 files changed, 13 insertions(+), 3 deletions(-) diff --git a/lib/x86/setup.c b/lib/x86/setup.c index 7dd6677..5d32d3f 100644 --- a/lib/x86/setup.c +++ b/lib/x86/setup.c @@ -170,7 +170,8 @@ void setup_multiboot(struct mbi_bootinfo *bi) #ifdef CONFIG_EFI /* From x86/efi/efistart64.S */ -extern void setup_segments64(void); +extern void setup_segments64(u64 gs_base); +extern u8 stacktop; static efi_status_t setup_memory_allocator(efi_bootinfo_t *efi_bootinfo) { @@ -271,12 +272,14 @@ static void setup_page_table(void) static void setup_gdt_tss(void) { size_t tss_offset; + u64 gs_base; /* 64-bit setup_tss does not use the stacktop argument. */ tss_offset = setup_tss(NULL); load_gdt_tss(tss_offset); - setup_segments64(); + gs_base = (u64)(&stacktop) - (PAGE_SIZE * (pre_boot_apic_id() + 1)); + setup_segments64(gs_base); } efi_status_t setup_efi(efi_bootinfo_t *efi_bootinfo) @@ -318,8 +321,8 @@ efi_status_t setup_efi(efi_bootinfo_t *efi_bootinfo) return status; } - reset_apic(); setup_gdt_tss(); + reset_apic(); setup_idt(); load_idt(); mask_pic_interrupts(); diff --git a/x86/efi/efistart64.S b/x86/efi/efistart64.S index cb08230..1c38355 100644 --- a/x86/efi/efistart64.S +++ b/x86/efi/efistart64.S @@ -44,6 +44,13 @@ setup_segments64: mov %ax, %gs mov %ax, %ss + /* Setup percpu base */ + MSR_GS_BASE = 0xc0000101 + mov %rdi, %rax + mov $0, %edx + mov $MSR_GS_BASE, %ecx + wrmsr + /* * Update the code segment by putting it on the stack before the return * address, then doing a far return: this will use the new code segment