| Message ID | 1456658360-16080-14-git-send-email-zhaoshenglong@huawei.com |
|---|---|
| State | Superseded |
| Headers | show |
On 2016年03月02日 01:01, Stefano Stabellini wrote: > On Tue, 1 Mar 2016, Stefano Stabellini wrote: >> > On Tue, 1 Mar 2016, Shannon Zhao wrote: >>> > > On 2016/2/29 22:15, Stefano Stabellini wrote: >>>> > > > On Sun, 28 Feb 2016, Shannon Zhao wrote: >>>>>> > > >> > From: Shannon Zhao <shannon.zhao@linaro.org> >>>>>> > > >> > >>>>>> > > >> > Map all other tables to Dom0 using 1:1 mappings. >>>>>> > > >> > >>>>>> > > >> > Signed-off-by: Shannon Zhao <shannon.zhao@linaro.org> >>>>>> > > >> > --- >>>>>> > > >> > v4: fix commit message >>>>>> > > >> > --- >>>>>> > > >> > xen/arch/arm/domain_build.c | 26 ++++++++++++++++++++++++++ >>>>>> > > >> > 1 file changed, 26 insertions(+) >>>>>> > > >> > >>>>>> > > >> > diff --git a/xen/arch/arm/domain_build.c b/xen/arch/arm/domain_build.c >>>>>> > > >> > index 64e48ae..6ad420c 100644 >>>>>> > > >> > --- a/xen/arch/arm/domain_build.c >>>>>> > > >> > +++ b/xen/arch/arm/domain_build.c >>>>>> > > >> > @@ -1357,6 +1357,30 @@ static int prepare_dtb(struct domain *d, struct kernel_info *kinfo) >>>>>> > > >> > } >>>>>> > > >> > >>>>>> > > >> > #ifdef CONFIG_ACPI >>>>>> > > >> > +static void acpi_map_other_tables(struct domain *d) >>>>>> > > >> > +{ >>>>>> > > >> > + int i; >>>>>> > > >> > + unsigned long res; >>>>>> > > >> > + u64 addr, size; >>>>>> > > >> > + >>>>>> > > >> > + /* Map all other tables to Dom0 using 1:1 mappings. */ >>>>>> > > >> > + for( i = 0; i < acpi_gbl_root_table_list.count; i++ ) >>>>>> > > >> > + { >>>>>> > > >> > + addr = acpi_gbl_root_table_list.tables[i].address; >>>>>> > > >> > + size = acpi_gbl_root_table_list.tables[i].length; >>>>>> > > >> > + res = map_regions(d, >>>>>> > > >> > + paddr_to_pfn(addr & PAGE_MASK), >>>>>> > > >> > + DIV_ROUND_UP(size, PAGE_SIZE), >>>>>> > > >> > + paddr_to_pfn(addr & PAGE_MASK)); >>>>>> > > >> > + if ( res ) >>>>>> > > >> > + { >>>>>> > > >> > + panic(XENLOG_ERR "Unable to map 0x%"PRIx64 >>>>>> > > >> > + " - 0x%"PRIx64" in domain \n", >>>>>> > > >> > + addr & PAGE_MASK, PAGE_ALIGN(addr + size) - 1); >>>>>> > > >> > + } >>>>>> > > >> > + } >>>>>> > > >> > +} >>>> > > > The problem with this function is that it is mapping all other tables to >>>> > > > the guest, including the unmodified FADT and MADT. This way dom0 is >>>> > > > going to find two different versions of the FADT and MADT, isn't that >>>> > > > right? >>>> > > > >>> > > We've replaced the entries of XSDT table with new value. That means XSDT >>> > > points to new table. Guest will not see the old ones. >> > >> > All right. Of course it would be best to avoid mapping the original FADT >> > and MADT at all, but given that they are not likely to be page aligned, >> > it wouldn't be easy to do. >> > >> > Reviewed-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com> > However I have one more question: given that map_regions maps the memory > read-only to Dom0, isn't it possible that one or more of the DSDT > functions could not work as expected? I would imagine that the ACPI > bytecode is allowed to change its own memory, right? > I'm not sure about this. But it seems that Xen or Linux always map these tables to its memory. Thanks, -- Shannon
diff --git a/xen/arch/arm/domain_build.c b/xen/arch/arm/domain_build.c index 64e48ae..6ad420c 100644 --- a/xen/arch/arm/domain_build.c +++ b/xen/arch/arm/domain_build.c @@ -1357,6 +1357,30 @@ static int prepare_dtb(struct domain *d, struct kernel_info *kinfo) } #ifdef CONFIG_ACPI +static void acpi_map_other_tables(struct domain *d) +{ + int i; + unsigned long res; + u64 addr, size; + + /* Map all other tables to Dom0 using 1:1 mappings. */ + for( i = 0; i < acpi_gbl_root_table_list.count; i++ ) + { + addr = acpi_gbl_root_table_list.tables[i].address; + size = acpi_gbl_root_table_list.tables[i].length; + res = map_regions(d, + paddr_to_pfn(addr & PAGE_MASK), + DIV_ROUND_UP(size, PAGE_SIZE), + paddr_to_pfn(addr & PAGE_MASK)); + if ( res ) + { + panic(XENLOG_ERR "Unable to map 0x%"PRIx64 + " - 0x%"PRIx64" in domain \n", + addr & PAGE_MASK, PAGE_ALIGN(addr + size) - 1); + } + } +} + static int acpi_create_rsdp(struct domain *d, struct membank tbl_add[]) { @@ -1661,6 +1685,8 @@ static int prepare_acpi(struct domain *d, struct kernel_info *kinfo) if ( rc != 0 ) return rc; + acpi_map_other_tables(d); + return 0; } #else