From nobody Thu Apr 9 02:36:53 2026 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 292E9C4332F for ; Thu, 3 Nov 2022 17:58:55 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231732AbiKCR6x (ORCPT ); Thu, 3 Nov 2022 13:58:53 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:35804 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231565AbiKCR6u (ORCPT ); Thu, 3 Nov 2022 13:58:50 -0400 Received: from linux.microsoft.com (linux.microsoft.com [13.77.154.182]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id 4CB9EE34; Thu, 3 Nov 2022 10:58:49 -0700 (PDT) Received: from skinsburskii-cloud-desktop.internal.cloudapp.net (unknown [20.120.152.163]) by linux.microsoft.com (Postfix) with ESMTPSA id 1AE5E20C28B1; Thu, 3 Nov 2022 10:58:49 -0700 (PDT) DKIM-Filter: OpenDKIM Filter v2.11.0 linux.microsoft.com 1AE5E20C28B1 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.microsoft.com; s=default; t=1667498329; bh=d2r8ZXf09V8uzug4END6ry4gGh3rPYlU3pv6NwpfdRE=; h=Subject:From:Cc:Date:In-Reply-To:References:From; b=BuTRr6tnaRl5ZUlXSNO6XGsV/dMn2Ht5Ei4eV3Ct2G3/TEDHXdYfDZzHZk4N9MVL8 fLU9cJOgE5JPuOl2n0VwK0sQhvsk/iVV+lFU8jwsUrTz0+SE+aVZLbc02Vbo9kIex9 VGcrWx8VBPiU1TyTzZajJR5S/gWSoRh+cu7+OhIg= Subject: [PATCH v3 1/4] drivers/clocksource/hyper-v: Introduce a pointer to TSC page From: Stanislav Kinsburskii Cc: Stanislav Kinsburskiy , "K. Y. Srinivasan" , Haiyang Zhang , Wei Liu , Dexuan Cui , Daniel Lezcano , Thomas Gleixner , linux-hyperv@vger.kernel.org, linux-kernel@vger.kernel.org, mikelley@microsoft.com Date: Thu, 03 Nov 2022 17:58:48 +0000 Message-ID: <166749832893.218190.16503272948154953294.stgit@skinsburskii-cloud-desktop.internal.cloudapp.net> In-Reply-To: <166749827889.218190.12775118554387271641.stgit@skinsburskii-cloud-desktop.internal.cloudapp.net> References: <166749827889.218190.12775118554387271641.stgit@skinsburskii-cloud-desktop.internal.cloudapp.net> User-Agent: StGit/0.19 MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable To: unlisted-recipients:; (no To-header on input) Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Stanislav Kinsburskiy Will be used later keep the address of the remapped page for the root partition as it will be Microsoft Hypervisor defined (and thus won't be a static address). Signed-off-by: Stanislav Kinsburskiy CC: "K. Y. Srinivasan" CC: Haiyang Zhang CC: Wei Liu CC: Dexuan Cui CC: Daniel Lezcano CC: Thomas Gleixner CC: linux-hyperv@vger.kernel.org CC: linux-kernel@vger.kernel.org Acked-by: Daniel Lezcano Reviewed-by: Michael Kelley --- drivers/clocksource/hyperv_timer.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/drivers/clocksource/hyperv_timer.c b/drivers/clocksource/hyper= v_timer.c index 18de1f439ffd..b0b5df576e17 100644 --- a/drivers/clocksource/hyperv_timer.c +++ b/drivers/clocksource/hyperv_timer.c @@ -367,9 +367,11 @@ static union { u8 reserved[PAGE_SIZE]; } tsc_pg __aligned(PAGE_SIZE); =20 +static struct ms_hyperv_tsc_page *tsc_page =3D &tsc_pg.page; + struct ms_hyperv_tsc_page *hv_get_tsc_page(void) { - return &tsc_pg.page; + return tsc_page; } EXPORT_SYMBOL_GPL(hv_get_tsc_page); =20 @@ -407,7 +409,7 @@ static void suspend_hv_clock_tsc(struct clocksource *ar= g) =20 static void resume_hv_clock_tsc(struct clocksource *arg) { - phys_addr_t phys_addr =3D virt_to_phys(&tsc_pg); + phys_addr_t phys_addr =3D virt_to_phys(tsc_page); union hv_reference_tsc_msr tsc_msr; =20 /* Re-enable the TSC page */ From nobody Thu Apr 9 02:36:53 2026 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 7C387C433FE for ; Thu, 3 Nov 2022 17:59:01 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231819AbiKCR7A (ORCPT ); Thu, 3 Nov 2022 13:59:00 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:36150 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231625AbiKCR6z (ORCPT ); Thu, 3 Nov 2022 13:58:55 -0400 Received: from linux.microsoft.com (linux.microsoft.com [13.77.154.182]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id 8C152100C; Thu, 3 Nov 2022 10:58:54 -0700 (PDT) Received: from skinsburskii-cloud-desktop.internal.cloudapp.net (unknown [20.120.152.163]) by linux.microsoft.com (Postfix) with ESMTPSA id 4986520C28B1; Thu, 3 Nov 2022 10:58:54 -0700 (PDT) DKIM-Filter: OpenDKIM Filter v2.11.0 linux.microsoft.com 4986520C28B1 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.microsoft.com; s=default; t=1667498334; bh=2oxuhDe5kV6GjYNF8LuxN2eAqqYyKVRUxh3NgSYoyro=; h=Subject:From:Cc:Date:In-Reply-To:References:From; b=JtO1ihxob+SsrhIVYTkWVTsjV7gq4+H3B+vaZm7VECZafo13jgTiSkJMxL4eMzgxl ysZwGbCvQQB0vqTrvA/roMYBcVli7TiT5gtv7f0ZW5vOPO0WzdUEGo0Lyx7WZLIMjR 2qB0HCpnLe3NKPPLYrTs6KrneWDt7cPfb1LZSZJU= Subject: [PATCH v3 2/4] drivers/clocksource/hyper-v: Introduce TSC PFN getter From: Stanislav Kinsburskii Cc: Stanislav Kinsburskiy , "K. Y. Srinivasan" , Haiyang Zhang , Wei Liu , Dexuan Cui , Daniel Lezcano , Thomas Gleixner , linux-hyperv@vger.kernel.org, linux-kernel@vger.kernel.org, mikelley@microsoft.com Date: Thu, 03 Nov 2022 17:58:54 +0000 Message-ID: <166749833420.218190.2102763345349472395.stgit@skinsburskii-cloud-desktop.internal.cloudapp.net> In-Reply-To: <166749827889.218190.12775118554387271641.stgit@skinsburskii-cloud-desktop.internal.cloudapp.net> References: <166749827889.218190.12775118554387271641.stgit@skinsburskii-cloud-desktop.internal.cloudapp.net> User-Agent: StGit/0.19 MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable To: unlisted-recipients:; (no To-header on input) Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Stanislav Kinsburskiy And rework the code to use it instead of the physical address, which isn't required by itself. This is a cleanup and precursor patch for upcoming support for TSC page mapping into Microsoft Hypervisor root partition, where TSC PFN will be defined by the hypervisor and not by the kernel. Signed-off-by: Stanislav Kinsburskiy CC: "K. Y. Srinivasan" CC: Haiyang Zhang CC: Wei Liu CC: Dexuan Cui CC: Daniel Lezcano CC: Thomas Gleixner CC: linux-hyperv@vger.kernel.org CC: linux-kernel@vger.kernel.org Acked-by: Daniel Lezcano Reviewed-by: Michael Kelley --- drivers/clocksource/hyperv_timer.c | 14 +++++++++----- 1 file changed, 9 insertions(+), 5 deletions(-) diff --git a/drivers/clocksource/hyperv_timer.c b/drivers/clocksource/hyper= v_timer.c index b0b5df576e17..b7af19d06b51 100644 --- a/drivers/clocksource/hyperv_timer.c +++ b/drivers/clocksource/hyperv_timer.c @@ -368,6 +368,12 @@ static union { } tsc_pg __aligned(PAGE_SIZE); =20 static struct ms_hyperv_tsc_page *tsc_page =3D &tsc_pg.page; +static unsigned long tsc_pfn; + +static unsigned long hv_get_tsc_pfn(void) +{ + return tsc_pfn; +} =20 struct ms_hyperv_tsc_page *hv_get_tsc_page(void) { @@ -409,13 +415,12 @@ static void suspend_hv_clock_tsc(struct clocksource *= arg) =20 static void resume_hv_clock_tsc(struct clocksource *arg) { - phys_addr_t phys_addr =3D virt_to_phys(tsc_page); union hv_reference_tsc_msr tsc_msr; =20 /* Re-enable the TSC page */ tsc_msr.as_uint64 =3D hv_get_register(HV_REGISTER_REFERENCE_TSC); tsc_msr.enable =3D 1; - tsc_msr.pfn =3D HVPFN_DOWN(phys_addr); + tsc_msr.pfn =3D tsc_pfn; hv_set_register(HV_REGISTER_REFERENCE_TSC, tsc_msr.as_uint64); } =20 @@ -499,7 +504,6 @@ static __always_inline void hv_setup_sched_clock(void *= sched_clock) {} static bool __init hv_init_tsc_clocksource(void) { union hv_reference_tsc_msr tsc_msr; - phys_addr_t phys_addr; =20 if (!(ms_hyperv.features & HV_MSR_REFERENCE_TSC_AVAILABLE)) return false; @@ -524,7 +528,7 @@ static bool __init hv_init_tsc_clocksource(void) } =20 hv_read_reference_counter =3D read_hv_clock_tsc; - phys_addr =3D virt_to_phys(hv_get_tsc_page()); + tsc_pfn =3D HVPFN_DOWN(virt_to_phys(tsc_page)); =20 /* * The Hyper-V TLFS specifies to preserve the value of reserved @@ -535,7 +539,7 @@ static bool __init hv_init_tsc_clocksource(void) */ tsc_msr.as_uint64 =3D hv_get_register(HV_REGISTER_REFERENCE_TSC); tsc_msr.enable =3D 1; - tsc_msr.pfn =3D HVPFN_DOWN(phys_addr); + tsc_msr.pfn =3D tsc_pfn; hv_set_register(HV_REGISTER_REFERENCE_TSC, tsc_msr.as_uint64); =20 clocksource_register_hz(&hyperv_cs_tsc, NSEC_PER_SEC/100); From nobody Thu Apr 9 02:36:53 2026 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 62AE0C433FE for ; Thu, 3 Nov 2022 17:59:21 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231664AbiKCR7T (ORCPT ); Thu, 3 Nov 2022 13:59:19 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:36478 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231881AbiKCR7I (ORCPT ); Thu, 3 Nov 2022 13:59:08 -0400 Received: from linux.microsoft.com (linux.microsoft.com [13.77.154.182]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id CB82B2197; Thu, 3 Nov 2022 10:58:59 -0700 (PDT) Received: from skinsburskii-cloud-desktop.internal.cloudapp.net (unknown [20.120.152.163]) by linux.microsoft.com (Postfix) with ESMTPSA id 8B0A5205DA3E; Thu, 3 Nov 2022 10:58:59 -0700 (PDT) DKIM-Filter: OpenDKIM Filter v2.11.0 linux.microsoft.com 8B0A5205DA3E DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.microsoft.com; s=default; t=1667498339; bh=Y5FIS1UinMZxnexhjB33RzhGI8ZZkhrWDexZaDMwgyw=; h=Subject:From:Cc:Date:In-Reply-To:References:From; b=LFRZUZTPZzXnmqxogF0vtBFfURfydGni/8XJCj3i6Dly0qcTr+ZmnBNAP/EoCqv6h +ijRhkhZ74WTb0VIpahmR7TLT1lJ+4H/xug34Tg+QS6Qo/lsamBOsZvJHS+8BkGYZo Pch+65CysJw0L85LGxwqrcXTMiY1bmZN/OmYsTCQ= Subject: [PATCH v3 3/4] drivers/clocksource/hyper-v: Use TSC PFN getter to map vvar page From: Stanislav Kinsburskii Cc: Stanislav Kinsburskiy , Andy Lutomirski , Thomas Gleixner , Ingo Molnar , Borislav Petkov , Dave Hansen , x86@kernel.org, "H. Peter Anvin" , "K. Y. Srinivasan" , Haiyang Zhang , Wei Liu , Dexuan Cui , Daniel Lezcano , linux-kernel@vger.kernel.org, linux-hyperv@vger.kernel.org, mikelley@microsoft.com Date: Thu, 03 Nov 2022 17:58:59 +0000 Message-ID: <166749833939.218190.14095015146003109462.stgit@skinsburskii-cloud-desktop.internal.cloudapp.net> In-Reply-To: <166749827889.218190.12775118554387271641.stgit@skinsburskii-cloud-desktop.internal.cloudapp.net> References: <166749827889.218190.12775118554387271641.stgit@skinsburskii-cloud-desktop.internal.cloudapp.net> User-Agent: StGit/0.19 MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable To: unlisted-recipients:; (no To-header on input) Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Stanislav Kinsburskiy Instead of converting the virtual address to physical directly. This is a precursor patch for the upcoming support for TSC page mapping into Microsoft Hypervisor root partition, where TSC PFN will be defined by the hypervisor and thus can't be obtained by linear translation of the physical address. Signed-off-by: Stanislav Kinsburskiy CC: Andy Lutomirski CC: Thomas Gleixner CC: Ingo Molnar CC: Borislav Petkov CC: Dave Hansen CC: x86@kernel.org CC: "H. Peter Anvin" CC: "K. Y. Srinivasan" CC: Haiyang Zhang CC: Wei Liu CC: Dexuan Cui CC: Daniel Lezcano CC: linux-kernel@vger.kernel.org CC: linux-hyperv@vger.kernel.org Acked-by: Daniel Lezcano Reviewed-by: Michael Kelley --- arch/x86/entry/vdso/vma.c | 7 +++---- drivers/clocksource/hyperv_timer.c | 3 ++- include/clocksource/hyperv_timer.h | 6 ++++++ 3 files changed, 11 insertions(+), 5 deletions(-) diff --git a/arch/x86/entry/vdso/vma.c b/arch/x86/entry/vdso/vma.c index 311eae30e089..6976416b2c9f 100644 --- a/arch/x86/entry/vdso/vma.c +++ b/arch/x86/entry/vdso/vma.c @@ -210,11 +210,10 @@ static vm_fault_t vvar_fault(const struct vm_special_= mapping *sm, pgprot_decrypted(vma->vm_page_prot)); } } else if (sym_offset =3D=3D image->sym_hvclock_page) { - struct ms_hyperv_tsc_page *tsc_pg =3D hv_get_tsc_page(); + pfn =3D hv_get_tsc_pfn(); =20 - if (tsc_pg && vclock_was_used(VDSO_CLOCKMODE_HVCLOCK)) - return vmf_insert_pfn(vma, vmf->address, - virt_to_phys(tsc_pg) >> PAGE_SHIFT); + if (pfn && vclock_was_used(VDSO_CLOCKMODE_HVCLOCK)) + return vmf_insert_pfn(vma, vmf->address, pfn); } else if (sym_offset =3D=3D image->sym_timens_page) { struct page *timens_page =3D find_timens_vvar_page(vma); =20 diff --git a/drivers/clocksource/hyperv_timer.c b/drivers/clocksource/hyper= v_timer.c index b7af19d06b51..9445a1558fe9 100644 --- a/drivers/clocksource/hyperv_timer.c +++ b/drivers/clocksource/hyperv_timer.c @@ -370,10 +370,11 @@ static union { static struct ms_hyperv_tsc_page *tsc_page =3D &tsc_pg.page; static unsigned long tsc_pfn; =20 -static unsigned long hv_get_tsc_pfn(void) +unsigned long hv_get_tsc_pfn(void) { return tsc_pfn; } +EXPORT_SYMBOL_GPL(hv_get_tsc_pfn); =20 struct ms_hyperv_tsc_page *hv_get_tsc_page(void) { diff --git a/include/clocksource/hyperv_timer.h b/include/clocksource/hyper= v_timer.h index b3f5d73ae1d6..3078d23faaea 100644 --- a/include/clocksource/hyperv_timer.h +++ b/include/clocksource/hyperv_timer.h @@ -32,6 +32,7 @@ extern void hv_stimer0_isr(void); =20 extern void hv_init_clocksource(void); =20 +extern unsigned long hv_get_tsc_pfn(void); extern struct ms_hyperv_tsc_page *hv_get_tsc_page(void); =20 static inline notrace u64 @@ -90,6 +91,11 @@ hv_read_tsc_page(const struct ms_hyperv_tsc_page *tsc_pg) } =20 #else /* CONFIG_HYPERV_TIMER */ +static inline unsigned long hv_get_tsc_pfn(void) +{ + return 0; +} + static inline struct ms_hyperv_tsc_page *hv_get_tsc_page(void) { return NULL; From nobody Thu Apr 9 02:36:53 2026 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 1BA64C433FE for ; Thu, 3 Nov 2022 17:59:31 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231945AbiKCR73 (ORCPT ); Thu, 3 Nov 2022 13:59:29 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:36110 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231935AbiKCR7K (ORCPT ); Thu, 3 Nov 2022 13:59:10 -0400 Received: from linux.microsoft.com (linux.microsoft.com [13.77.154.182]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id 0E70D264F; Thu, 3 Nov 2022 10:59:05 -0700 (PDT) Received: from skinsburskii-cloud-desktop.internal.cloudapp.net (unknown [20.120.152.163]) by linux.microsoft.com (Postfix) with ESMTPSA id CB3D120C3338; Thu, 3 Nov 2022 10:59:04 -0700 (PDT) DKIM-Filter: OpenDKIM Filter v2.11.0 linux.microsoft.com CB3D120C3338 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.microsoft.com; s=default; t=1667498344; bh=++SExWSpMkq0Dv7lblZI7lZBKKts6IU3NqmxJpdUgoo=; h=Subject:From:Cc:Date:In-Reply-To:References:From; b=bJcsAsXG7mKa0C51B997E5v1xmj3NZw0x86iDTf8jVX4gDFtfc8GZUBIDCyTJkjJx eyvs8bOHYj0dcHpu4RpJS/EZ5ZR+2cPmWECzeSSxTd6ppWsIsyyqeb9O5Ju9sN6k2p pOh8ETzkwWKr2nZfT9V4iI9vQZh2cErZ4T/njDpo= Subject: [PATCH v3 4/4] drivers/clocksource/hyper-v: Add TSC page support for root partition From: Stanislav Kinsburskii Cc: Stanislav Kinsburskiy , "K. Y. Srinivasan" , Haiyang Zhang , Wei Liu , Dexuan Cui , Thomas Gleixner , Ingo Molnar , Borislav Petkov , Dave Hansen , x86@kernel.org, "H. Peter Anvin" , Daniel Lezcano , linux-hyperv@vger.kernel.org, linux-kernel@vger.kernel.org, mikelley@microsoft.com Date: Thu, 03 Nov 2022 17:59:04 +0000 Message-ID: <166749834466.218190.3482871684875422987.stgit@skinsburskii-cloud-desktop.internal.cloudapp.net> In-Reply-To: <166749827889.218190.12775118554387271641.stgit@skinsburskii-cloud-desktop.internal.cloudapp.net> References: <166749827889.218190.12775118554387271641.stgit@skinsburskii-cloud-desktop.internal.cloudapp.net> User-Agent: StGit/0.19 MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable To: unlisted-recipients:; (no To-header on input) Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Stanislav Kinsburskiy Microsoft Hypervisor root partition has to map the TSC page specified by the hypervisor, instead of providing the page to the hypervisor like it's done in the guest partitions. However, it's too early to map the page when the clock is initialized, so, = the actual mapping is happening later. Signed-off-by: Stanislav Kinsburskiy CC: "K. Y. Srinivasan" CC: Haiyang Zhang CC: Wei Liu CC: Dexuan Cui CC: Thomas Gleixner CC: Ingo Molnar CC: Borislav Petkov CC: Dave Hansen CC: x86@kernel.org CC: "H. Peter Anvin" CC: Daniel Lezcano CC: linux-hyperv@vger.kernel.org CC: linux-kernel@vger.kernel.org Acked-by: Daniel Lezcano --- arch/x86/hyperv/hv_init.c | 2 ++ drivers/clocksource/hyperv_timer.c | 38 +++++++++++++++++++++++++++-----= ---- include/clocksource/hyperv_timer.h | 1 + 3 files changed, 32 insertions(+), 9 deletions(-) diff --git a/arch/x86/hyperv/hv_init.c b/arch/x86/hyperv/hv_init.c index f49bc3ec76e6..89954490af93 100644 --- a/arch/x86/hyperv/hv_init.c +++ b/arch/x86/hyperv/hv_init.c @@ -464,6 +464,8 @@ void __init hyperv_init(void) BUG_ON(!src); memcpy_to_page(pg, 0, src, HV_HYP_PAGE_SIZE); memunmap(src); + + hv_remap_tsc_clocksource(); } else { hypercall_msr.guest_physical_address =3D vmalloc_to_pfn(hv_hypercall_pg); wrmsrl(HV_X64_MSR_HYPERCALL, hypercall_msr.as_uint64); diff --git a/drivers/clocksource/hyperv_timer.c b/drivers/clocksource/hyper= v_timer.c index 9445a1558fe9..dec7ad3b85ba 100644 --- a/drivers/clocksource/hyperv_timer.c +++ b/drivers/clocksource/hyperv_timer.c @@ -509,9 +509,6 @@ static bool __init hv_init_tsc_clocksource(void) if (!(ms_hyperv.features & HV_MSR_REFERENCE_TSC_AVAILABLE)) return false; =20 - if (hv_root_partition) - return false; - /* * If Hyper-V offers TSC_INVARIANT, then the virtualized TSC correctly * handles frequency and offset changes due to live migration, @@ -529,16 +526,22 @@ static bool __init hv_init_tsc_clocksource(void) } =20 hv_read_reference_counter =3D read_hv_clock_tsc; - tsc_pfn =3D HVPFN_DOWN(virt_to_phys(tsc_page)); =20 /* - * The Hyper-V TLFS specifies to preserve the value of reserved - * bits in registers. So read the existing value, preserve the - * low order 12 bits, and add in the guest physical address - * (which already has at least the low 12 bits set to zero since - * it is page aligned). Also set the "enable" bit, which is bit 0. + * TSC page mapping works differently in root compared to guest. + * - In guest partition the guest PFN has to be passed to the + * hypervisor. + * - In root partition it's other way around: it has to map the PFN + * provided by the hypervisor. + * But it can't be mapped right here as it's too early and MMU isn't + * ready yet. So, we only set the enable bit here and will remap the + * page later in hv_remap_tsc_clocksource(). */ tsc_msr.as_uint64 =3D hv_get_register(HV_REGISTER_REFERENCE_TSC); + if (hv_root_partition) + tsc_pfn =3D tsc_msr.pfn; + else + tsc_pfn =3D HVPFN_DOWN(virt_to_phys(tsc_page)); tsc_msr.enable =3D 1; tsc_msr.pfn =3D tsc_pfn; hv_set_register(HV_REGISTER_REFERENCE_TSC, tsc_msr.as_uint64); @@ -573,3 +576,20 @@ void __init hv_init_clocksource(void) hv_sched_clock_offset =3D hv_read_reference_counter(); hv_setup_sched_clock(read_hv_sched_clock_msr); } + +void __init hv_remap_tsc_clocksource(void) +{ + if (!(ms_hyperv.features & HV_MSR_REFERENCE_TSC_AVAILABLE)) + return; + + if (!hv_root_partition) { + WARN(1, "%s: attempt to remap TSC page in guest partition\n", + __func__); + return; + } + + tsc_page =3D memremap(tsc_pfn << HV_HYP_PAGE_SHIFT, sizeof(tsc_pg), + MEMREMAP_WB); + if (!tsc_page) + pr_err("Failed to remap Hyper-V TSC page.\n"); +} diff --git a/include/clocksource/hyperv_timer.h b/include/clocksource/hyper= v_timer.h index 3078d23faaea..783701a2102d 100644 --- a/include/clocksource/hyperv_timer.h +++ b/include/clocksource/hyperv_timer.h @@ -31,6 +31,7 @@ extern void hv_stimer_global_cleanup(void); extern void hv_stimer0_isr(void); =20 extern void hv_init_clocksource(void); +extern void hv_remap_tsc_clocksource(void); =20 extern unsigned long hv_get_tsc_pfn(void); extern struct ms_hyperv_tsc_page *hv_get_tsc_page(void);