| Message ID | 5049B2FF02000078000998F3@nat28.tlf.novell.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Fri, 2012-09-07 at 07:40 +0100, Jan Beulich wrote: > At least for Xen Dom0 it is very relevant to set the _PAGE_IO bit when > ioremap-ing (non-RAM) areas, as that flag suppresses the PFN -> MFN > translation otherwise done in PV guests. (The offending commit was > 81e88fdc432a1552401d6e91a984dcccce72b8dc.) If my understanding were correct, ghes_ioremap_pfn_nmi normally only map RAM. Best Regards, Huang Ying -- To unsubscribe from this list: send the line "unsubscribe linux-acpi" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
>>> On 07.09.12 at 09:02, Huang Ying <ying.huang@intel.com> wrote: > On Fri, 2012-09-07 at 07:40 +0100, Jan Beulich wrote: >> At least for Xen Dom0 it is very relevant to set the _PAGE_IO bit when >> ioremap-ing (non-RAM) areas, as that flag suppresses the PFN -> MFN >> translation otherwise done in PV guests. (The offending commit was >> 81e88fdc432a1552401d6e91a984dcccce72b8dc.) > > If my understanding were correct, ghes_ioremap_pfn_nmi normally only map > RAM. But not RAM in the sense of what is seen as usable memory in the E820 map. What you're mapping here is reserved memory, and that is (from the perspective of the kernel and Xen) non-RAM. The fact that it is RAM from a machine perspective is manifested by the mapping not needing to be done UC or alike. Jan -- To unsubscribe from this list: send the line "unsubscribe linux-acpi" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Fri, Sep 07, 2012 at 07:40:31AM +0100, Jan Beulich wrote: > Date: Fri, 07 Sep 2012 07:40:31 +0100 > From: Jan Beulich <JBeulich@suse.com> > To: Len Brown <lenb@kernel.org> > Cc: ying.huang@intel.com, Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>, > linux-acpi@vger.kernel.org > Subject: [PATCH] GHES: correct page protection flags in > ghes_ioremap_pfn_...() > X-Mailer: Novell GroupWise Internet Agent 12.0.0 > > At least for Xen Dom0 it is very relevant to set the _PAGE_IO bit when > ioremap-ing (non-RAM) areas, as that flag suppresses the PFN -> MFN > translation otherwise done in PV guests. (The offending commit was > 81e88fdc432a1552401d6e91a984dcccce72b8dc.) > Oh, right. In virtual environment, physical address is virtualized, too. We need to tell *ioremap* to map in proper address space. But I want to do if you can update all related mappings for APEI tables? I'm not sure if all APEI tables are affected by this issue. > > Signed-off-by: Jan Beulich <jbeulich@suse.com> > Cc: Huang Ying <ying.huang@intel.com> > Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> > > --- > drivers/acpi/apei/ghes.c | 4 ++-- > 1 file changed, 2 insertions(+), 2 deletions(-) > > --- 3.6-rc4/drivers/acpi/apei/ghes.c > +++ 3.6-rc4-ghes-ioremap-prot/drivers/acpi/apei/ghes.c > @@ -206,7 +206,7 @@ static void __iomem *ghes_ioremap_pfn_nm > > vaddr = (unsigned long)GHES_IOREMAP_NMI_PAGE(ghes_ioremap_area->addr); > ioremap_page_range(vaddr, vaddr + PAGE_SIZE, > - pfn << PAGE_SHIFT, PAGE_KERNEL); > + pfn << PAGE_SHIFT, PAGE_KERNEL_IO); > > return (void __iomem *)vaddr; > } > @@ -217,7 +217,7 @@ static void __iomem *ghes_ioremap_pfn_ir > > vaddr = (unsigned long)GHES_IOREMAP_IRQ_PAGE(ghes_ioremap_area->addr); > ioremap_page_range(vaddr, vaddr + PAGE_SIZE, > - pfn << PAGE_SHIFT, PAGE_KERNEL); > + pfn << PAGE_SHIFT, PAGE_KERNEL_IO); > > return (void __iomem *)vaddr; > } > > > > -- > To unsubscribe from this list: send the line "unsubscribe linux-acpi" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html
>>> On 07.09.12 at 09:18, Chen Gong <gong.chen@linux.intel.com> wrote: > On Fri, Sep 07, 2012 at 07:40:31AM +0100, Jan Beulich wrote: >> Date: Fri, 07 Sep 2012 07:40:31 +0100 >> From: Jan Beulich <JBeulich@suse.com> >> To: Len Brown <lenb@kernel.org> >> Cc: ying.huang@intel.com, Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>, >> linux-acpi@vger.kernel.org >> Subject: [PATCH] GHES: correct page protection flags in >> ghes_ioremap_pfn_...() >> X-Mailer: Novell GroupWise Internet Agent 12.0.0 >> >> At least for Xen Dom0 it is very relevant to set the _PAGE_IO bit when >> ioremap-ing (non-RAM) areas, as that flag suppresses the PFN -> MFN >> translation otherwise done in PV guests. (The offending commit was >> 81e88fdc432a1552401d6e91a984dcccce72b8dc.) >> > > Oh, right. In virtual environment, physical address is virtualized, too. > We need to tell *ioremap* to map in proper address space. But I want > to do if you can update all related mappings for APEI tables? I'm not sure > if all APEI tables are affected by this issue. The other mappings that I found might be relevant use ioremap(), i.e. don't specify protection flags on their own. Jan -- To unsubscribe from this list: send the line "unsubscribe linux-acpi" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Fri, 2012-09-07 at 08:12 +0100, Jan Beulich wrote: > >>> On 07.09.12 at 09:02, Huang Ying <ying.huang@intel.com> wrote: > > On Fri, 2012-09-07 at 07:40 +0100, Jan Beulich wrote: > >> At least for Xen Dom0 it is very relevant to set the _PAGE_IO bit when > >> ioremap-ing (non-RAM) areas, as that flag suppresses the PFN -> MFN > >> translation otherwise done in PV guests. (The offending commit was > >> 81e88fdc432a1552401d6e91a984dcccce72b8dc.) > > > > If my understanding were correct, ghes_ioremap_pfn_nmi normally only map > > RAM. > > But not RAM in the sense of what is seen as usable memory in the > E820 map. What you're mapping here is reserved memory, and that > is (from the perspective of the kernel and Xen) non-RAM. The fact > that it is RAM from a machine perspective is manifested by the > mapping not needing to be done UC or alike. I think the key is to keep these memory range map consistent between each other. BIOS may map these memory cached. ACPI may mapped them as cached (see acpi_os_ioremap) too. Best Regards, Huang Ying -- To unsubscribe from this list: send the line "unsubscribe linux-acpi" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
>>> On 07.09.12 at 10:46, Huang Ying <ying.huang@intel.com> wrote: > On Fri, 2012-09-07 at 08:12 +0100, Jan Beulich wrote: >> >>> On 07.09.12 at 09:02, Huang Ying <ying.huang@intel.com> wrote: >> > On Fri, 2012-09-07 at 07:40 +0100, Jan Beulich wrote: >> >> At least for Xen Dom0 it is very relevant to set the _PAGE_IO bit when >> >> ioremap-ing (non-RAM) areas, as that flag suppresses the PFN -> MFN >> >> translation otherwise done in PV guests. (The offending commit was >> >> 81e88fdc432a1552401d6e91a984dcccce72b8dc.) >> > >> > If my understanding were correct, ghes_ioremap_pfn_nmi normally only map >> > RAM. >> >> But not RAM in the sense of what is seen as usable memory in the >> E820 map. What you're mapping here is reserved memory, and that >> is (from the perspective of the kernel and Xen) non-RAM. The fact >> that it is RAM from a machine perspective is manifested by the >> mapping not needing to be done UC or alike. > > I think the key is to keep these memory range map consistent between > each other. BIOS may map these memory cached. ACPI may mapped them as > cached (see acpi_os_ioremap) too. But that aspect is orthogonal to the patch here - all we need done for Xen is the proper setting of _PAGE_IO; cachability is being dealt with independently (and correctly I think). Jan -- To unsubscribe from this list: send the line "unsubscribe linux-acpi" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Fri, 2012-09-07 at 09:51 +0100, Jan Beulich wrote: > >>> On 07.09.12 at 10:46, Huang Ying <ying.huang@intel.com> wrote: > > On Fri, 2012-09-07 at 08:12 +0100, Jan Beulich wrote: > >> >>> On 07.09.12 at 09:02, Huang Ying <ying.huang@intel.com> wrote: > >> > On Fri, 2012-09-07 at 07:40 +0100, Jan Beulich wrote: > >> >> At least for Xen Dom0 it is very relevant to set the _PAGE_IO bit when > >> >> ioremap-ing (non-RAM) areas, as that flag suppresses the PFN -> MFN > >> >> translation otherwise done in PV guests. (The offending commit was > >> >> 81e88fdc432a1552401d6e91a984dcccce72b8dc.) > >> > > >> > If my understanding were correct, ghes_ioremap_pfn_nmi normally only map > >> > RAM. > >> > >> But not RAM in the sense of what is seen as usable memory in the > >> E820 map. What you're mapping here is reserved memory, and that > >> is (from the perspective of the kernel and Xen) non-RAM. The fact > >> that it is RAM from a machine perspective is manifested by the > >> mapping not needing to be done UC or alike. > > > > I think the key is to keep these memory range map consistent between > > each other. BIOS may map these memory cached. ACPI may mapped them as > > cached (see acpi_os_ioremap) too. > > But that aspect is orthogonal to the patch here - all we need > done for Xen is the proper setting of _PAGE_IO; cachability > is being dealt with independently (and correctly I think). Sorry, don't know much about Xen. Just think we should keep mapping consistent about whether cached in native environment. Best Regards, Huang Ying -- To unsubscribe from this list: send the line "unsubscribe linux-acpi" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
>>> On 07.09.12 at 10:55, Huang Ying <ying.huang@intel.com> wrote: > On Fri, 2012-09-07 at 09:51 +0100, Jan Beulich wrote: >> >>> On 07.09.12 at 10:46, Huang Ying <ying.huang@intel.com> wrote: >> > On Fri, 2012-09-07 at 08:12 +0100, Jan Beulich wrote: >> >> >>> On 07.09.12 at 09:02, Huang Ying <ying.huang@intel.com> wrote: >> >> > On Fri, 2012-09-07 at 07:40 +0100, Jan Beulich wrote: >> >> >> At least for Xen Dom0 it is very relevant to set the _PAGE_IO bit when >> >> >> ioremap-ing (non-RAM) areas, as that flag suppresses the PFN -> MFN >> >> >> translation otherwise done in PV guests. (The offending commit was >> >> >> 81e88fdc432a1552401d6e91a984dcccce72b8dc.) >> >> > >> >> > If my understanding were correct, ghes_ioremap_pfn_nmi normally only map >> >> > RAM. >> >> >> >> But not RAM in the sense of what is seen as usable memory in the >> >> E820 map. What you're mapping here is reserved memory, and that >> >> is (from the perspective of the kernel and Xen) non-RAM. The fact >> >> that it is RAM from a machine perspective is manifested by the >> >> mapping not needing to be done UC or alike. >> > >> > I think the key is to keep these memory range map consistent between >> > each other. BIOS may map these memory cached. ACPI may mapped them as >> > cached (see acpi_os_ioremap) too. >> >> But that aspect is orthogonal to the patch here - all we need >> done for Xen is the proper setting of _PAGE_IO; cachability >> is being dealt with independently (and correctly I think). > > Sorry, don't know much about Xen. Just think we should keep mapping > consistent about whether cached in native environment. Of course. And nothing changes with the patch in that regard. Jan -- To unsubscribe from this list: send the line "unsubscribe linux-acpi" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Fri, 2012-09-07 at 10:02 +0100, Jan Beulich wrote: > >>> On 07.09.12 at 10:55, Huang Ying <ying.huang@intel.com> wrote: > > On Fri, 2012-09-07 at 09:51 +0100, Jan Beulich wrote: > >> >>> On 07.09.12 at 10:46, Huang Ying <ying.huang@intel.com> wrote: > >> > On Fri, 2012-09-07 at 08:12 +0100, Jan Beulich wrote: > >> >> >>> On 07.09.12 at 09:02, Huang Ying <ying.huang@intel.com> wrote: > >> >> > On Fri, 2012-09-07 at 07:40 +0100, Jan Beulich wrote: > >> >> >> At least for Xen Dom0 it is very relevant to set the _PAGE_IO bit when > >> >> >> ioremap-ing (non-RAM) areas, as that flag suppresses the PFN -> MFN > >> >> >> translation otherwise done in PV guests. (The offending commit was > >> >> >> 81e88fdc432a1552401d6e91a984dcccce72b8dc.) > >> >> > > >> >> > If my understanding were correct, ghes_ioremap_pfn_nmi normally only map > >> >> > RAM. > >> >> > >> >> But not RAM in the sense of what is seen as usable memory in the > >> >> E820 map. What you're mapping here is reserved memory, and that > >> >> is (from the perspective of the kernel and Xen) non-RAM. The fact > >> >> that it is RAM from a machine perspective is manifested by the > >> >> mapping not needing to be done UC or alike. > >> > > >> > I think the key is to keep these memory range map consistent between > >> > each other. BIOS may map these memory cached. ACPI may mapped them as > >> > cached (see acpi_os_ioremap) too. > >> > >> But that aspect is orthogonal to the patch here - all we need > >> done for Xen is the proper setting of _PAGE_IO; cachability > >> is being dealt with independently (and correctly I think). > > > > Sorry, don't know much about Xen. Just think we should keep mapping > > consistent about whether cached in native environment. > > Of course. And nothing changes with the patch in that regard. Yes. So I have no objection to the patch. Reviewed-by: Huang Ying <ying.huang@intel.com> Best Regards, Huang Ying -- To unsubscribe from this list: send the line "unsubscribe linux-acpi" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
--- 3.6-rc4/drivers/acpi/apei/ghes.c +++ 3.6-rc4-ghes-ioremap-prot/drivers/acpi/apei/ghes.c @@ -206,7 +206,7 @@ static void __iomem *ghes_ioremap_pfn_nm vaddr = (unsigned long)GHES_IOREMAP_NMI_PAGE(ghes_ioremap_area->addr); ioremap_page_range(vaddr, vaddr + PAGE_SIZE, - pfn << PAGE_SHIFT, PAGE_KERNEL); + pfn << PAGE_SHIFT, PAGE_KERNEL_IO); return (void __iomem *)vaddr; } @@ -217,7 +217,7 @@ static void __iomem *ghes_ioremap_pfn_ir vaddr = (unsigned long)GHES_IOREMAP_IRQ_PAGE(ghes_ioremap_area->addr); ioremap_page_range(vaddr, vaddr + PAGE_SIZE, - pfn << PAGE_SHIFT, PAGE_KERNEL); + pfn << PAGE_SHIFT, PAGE_KERNEL_IO); return (void __iomem *)vaddr; }
At least for Xen Dom0 it is very relevant to set the _PAGE_IO bit when ioremap-ing (non-RAM) areas, as that flag suppresses the PFN -> MFN translation otherwise done in PV guests. (The offending commit was 81e88fdc432a1552401d6e91a984dcccce72b8dc.) Signed-off-by: Jan Beulich <jbeulich@suse.com> Cc: Huang Ying <ying.huang@intel.com> Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> --- drivers/acpi/apei/ghes.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) -- To unsubscribe from this list: send the line "unsubscribe linux-acpi" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html