| Message ID | 1519842483-8887-7-git-send-email-maran.wilson@oracle.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On 28/02/18 19:28, Maran Wilson wrote: > The start info structure that is defined as part of the x86/HVM direct boot > ABI and used for starting Xen PVH guests would be more versatile if it also > included a way to pass information about the memory map to the guest. This > would allow KVM guests to share the same entry point. > > Signed-off-by: Maran Wilson <maran.wilson@oracle.com> I'm fine with this, but we need this change being accepted by the Xen community first. So an Ack from Jan or Andrew is required as the same change should be done on Xen side. Juergen
>>>> Juergen Gross <jgross@suse.com> 03/01/18 8:29 AM >>> >On 28/02/18 19:28, Maran Wilson wrote: >> The start info structure that is defined as part of the x86/HVM direct boot >> ABI and used for starting Xen PVH guests would be more versatile if it also >> included a way to pass information about the memory map to the guest. This >> would allow KVM guests to share the same entry point. >> >> Signed-off-by: Maran Wilson <maran.wilson@oracle.com> > >I'm fine with this, but we need this change being accepted by the Xen >community first. So an Ack from Jan or Andrew is required as the same >change should be done on Xen side. And for an ack to be given I continue to demand that a patch be sent against the Xen tree. That said, the change looks fine to me now (as indicated before). Jan
On Wed, Feb 28, 2018 at 10:28:02AM -0800, Maran Wilson wrote: > The start info structure that is defined as part of the x86/HVM direct boot > ABI and used for starting Xen PVH guests would be more versatile if it also > included a way to pass information about the memory map to the guest. This > would allow KVM guests to share the same entry point. > > Signed-off-by: Maran Wilson <maran.wilson@oracle.com> > --- > include/xen/interface/hvm/start_info.h | 50 +++++++++++++++++++++++++++++++++- > 1 file changed, 49 insertions(+), 1 deletion(-) > > diff --git a/include/xen/interface/hvm/start_info.h b/include/xen/interface/hvm/start_info.h > index 648415976ead..80cfbd35c1af 100644 > --- a/include/xen/interface/hvm/start_info.h > +++ b/include/xen/interface/hvm/start_info.h > @@ -33,7 +33,7 @@ > * | magic | Contains the magic value XEN_HVM_START_MAGIC_VALUE > * | | ("xEn3" with the 0x80 bit of the "E" set). > * 4 +----------------+ > - * | version | Version of this structure. Current version is 0. New > + * | version | Version of this structure. Current version is 1. New Have you checked if there are any OSes that end up checking this value at all? Perhaps also expand the comment to say that for PV guests only 0 is allowed. For PVH 0 or 1 is allowed ?
On 2/28/2018 11:41 PM, Jan Beulich wrote: >>>>> Juergen Gross <jgross@suse.com> 03/01/18 8:29 AM >>> >> On 28/02/18 19:28, Maran Wilson wrote: >>> The start info structure that is defined as part of the x86/HVM direct boot >>> ABI and used for starting Xen PVH guests would be more versatile if it also >>> included a way to pass information about the memory map to the guest. This >>> would allow KVM guests to share the same entry point. >>> >>> Signed-off-by: Maran Wilson <maran.wilson@oracle.com> >> I'm fine with this, but we need this change being accepted by the Xen >> community first. So an Ack from Jan or Andrew is required as the same >> change should be done on Xen side. > And for an ack to be given I continue to demand that a patch be sent against > the Xen tree. That said, the change looks fine to me now (as indicated before). Yes, I plan to send that out against the Xen tree shortly. Thanks, -Maran > Jan >
diff --git a/include/xen/interface/hvm/start_info.h b/include/xen/interface/hvm/start_info.h index 648415976ead..80cfbd35c1af 100644 --- a/include/xen/interface/hvm/start_info.h +++ b/include/xen/interface/hvm/start_info.h @@ -33,7 +33,7 @@ * | magic | Contains the magic value XEN_HVM_START_MAGIC_VALUE * | | ("xEn3" with the 0x80 bit of the "E" set). * 4 +----------------+ - * | version | Version of this structure. Current version is 0. New + * | version | Version of this structure. Current version is 1. New * | | versions are guaranteed to be backwards-compatible. * 8 +----------------+ * | flags | SIF_xxx flags. @@ -48,6 +48,15 @@ * 32 +----------------+ * | rsdp_paddr | Physical address of the RSDP ACPI data structure. * 40 +----------------+ + * | memmap_paddr | Physical address of the (optional) memory map. Only + * | | present in version 1 and newer of the structure. + * 48 +----------------+ + * | memmap_entries | Number of entries in the memory map table. Only + * | | present in version 1 and newer of the structure. + * | | Zero if there is no memory map being provided. + * 52 +----------------+ + * | reserved | Version 1 and newer only. + * 56 +----------------+ * * The layout of each entry in the module structure is the following: * @@ -62,10 +71,34 @@ * | reserved | * 32 +----------------+ * + * The layout of each entry in the memory map table is as follows: + * + * 0 +----------------+ + * | addr | Base address + * 8 +----------------+ + * | size | Size of mapping in bytes + * 16 +----------------+ + * | type | Type of mapping as defined between the hypervisor + * | | and guest it's starting. E820_TYPE_xxx, for example. + * 20 +----------------| + * | reserved | + * 24 +----------------+ + * * The address and sizes are always a 64bit little endian unsigned integer. * * NB: Xen on x86 will always try to place all the data below the 4GiB * boundary. + * + * Version numbers of the hvm_start_info structure have evolved like this: + * + * Version 0: + * + * Version 1: Added the memmap_paddr/memmap_entries fields (plus 4 bytes of + * padding) to the end of the hvm_start_info struct. These new + * fields can be used to pass a memory map to the guest. The + * memory map is optional and so guests that understand version 1 + * of the structure must check that memmap_entries is non-zero + * before trying to read the memory map. */ #define XEN_HVM_START_MAGIC_VALUE 0x336ec578 @@ -86,6 +119,14 @@ struct hvm_start_info { uint64_t cmdline_paddr; /* Physical address of the command line. */ uint64_t rsdp_paddr; /* Physical address of the RSDP ACPI data */ /* structure. */ + uint64_t memmap_paddr; /* Physical address of an array of */ + /* hvm_memmap_table_entry. Only present in */ + /* version 1 and newer of the structure */ + uint32_t memmap_entries; /* Number of entries in the memmap table. */ + /* Only present in version 1 and newer of */ + /* the structure. Value will be zero if */ + /* there is no memory map being provided. */ + uint32_t reserved; }; struct hvm_modlist_entry { @@ -95,4 +136,11 @@ struct hvm_modlist_entry { uint64_t reserved; }; +struct hvm_memmap_table_entry { + uint64_t addr; /* Base address of the memory region */ + uint64_t size; /* Size of the memory region in bytes */ + uint32_t type; /* Mapping type */ + uint32_t reserved; +}; + #endif /* __XEN_PUBLIC_ARCH_X86_HVM_START_INFO_H__ */
The start info structure that is defined as part of the x86/HVM direct boot ABI and used for starting Xen PVH guests would be more versatile if it also included a way to pass information about the memory map to the guest. This would allow KVM guests to share the same entry point. Signed-off-by: Maran Wilson <maran.wilson@oracle.com> --- include/xen/interface/hvm/start_info.h | 50 +++++++++++++++++++++++++++++++++- 1 file changed, 49 insertions(+), 1 deletion(-)