diff options
Diffstat (limited to '0051-libxl-docs-Use-arch-specific-default-paging-memory.patch')
| -rw-r--r-- | 0051-libxl-docs-Use-arch-specific-default-paging-memory.patch | 147 |
1 files changed, 147 insertions, 0 deletions
diff --git a/0051-libxl-docs-Use-arch-specific-default-paging-memory.patch b/0051-libxl-docs-Use-arch-specific-default-paging-memory.patch new file mode 100644 index 0000000..f3bded4 --- /dev/null +++ b/0051-libxl-docs-Use-arch-specific-default-paging-memory.patch @@ -0,0 +1,147 @@ +From 0c0680d6e7953ca4c91699e60060c732f9ead5c1 Mon Sep 17 00:00:00 2001 +From: Henry Wang <Henry.Wang@arm.com> +Date: Tue, 11 Oct 2022 15:09:32 +0200 +Subject: [PATCH 51/67] libxl, docs: Use arch-specific default paging memory + +The default paging memory (descibed in `shadow_memory` entry in xl +config) in libxl is used to determine the memory pool size for xl +guests. Currently this size is only used for x86, and contains a part +of RAM to shadow the resident processes. Since on Arm there is no +shadow mode guests, so the part of RAM to shadow the resident processes +is not necessary. Therefore, this commit splits the function +`libxl_get_required_shadow_memory()` to arch specific helpers and +renamed the helper to `libxl__arch_get_required_paging_memory()`. + +On x86, this helper calls the original value from +`libxl_get_required_shadow_memory()` so no functional change intended. + +On Arm, this helper returns 1MB per vcpu plus 4KB per MiB of RAM +for the P2M map and additional 512KB. + +Also update the xl.cfg documentation to add Arm documentation +according to code changes and correct the comment style following Xen +coding style. + +This is part of CVE-2022-33747 / XSA-409. + +Suggested-by: Julien Grall <jgrall@amazon.com> +Signed-off-by: Henry Wang <Henry.Wang@arm.com> +Reviewed-by: Anthony PERARD <anthony.perard@citrix.com> +master commit: 156a239ea288972425f967ac807b3cb5b5e14874 +master date: 2022-10-11 14:28:37 +0200 +--- + docs/man/xl.cfg.5.pod.in | 5 +++++ + tools/libs/light/libxl_arch.h | 4 ++++ + tools/libs/light/libxl_arm.c | 12 ++++++++++++ + tools/libs/light/libxl_utils.c | 9 ++------- + tools/libs/light/libxl_x86.c | 13 +++++++++++++ + 5 files changed, 36 insertions(+), 7 deletions(-) + +diff --git a/docs/man/xl.cfg.5.pod.in b/docs/man/xl.cfg.5.pod.in +index 56370a37dbb1..af7fae7c52f9 100644 +--- a/docs/man/xl.cfg.5.pod.in ++++ b/docs/man/xl.cfg.5.pod.in +@@ -1746,6 +1746,11 @@ are not using hardware assisted paging (i.e. you are using shadow + mode) and your guest workload consists of a very large number of + similar processes then increasing this value may improve performance. + ++On Arm, this field is used to determine the size of the guest P2M pages ++pool, and the default value is 1MB per vCPU plus 4KB per MB of RAM for ++the P2M map. Users should adjust this value if bigger P2M pool size is ++needed. ++ + =back + + =head3 Processor and Platform Features +diff --git a/tools/libs/light/libxl_arch.h b/tools/libs/light/libxl_arch.h +index 8527fc5c6c23..6741b7f6f457 100644 +--- a/tools/libs/light/libxl_arch.h ++++ b/tools/libs/light/libxl_arch.h +@@ -90,6 +90,10 @@ void libxl__arch_update_domain_config(libxl__gc *gc, + libxl_domain_config *dst, + const libxl_domain_config *src); + ++_hidden ++unsigned long libxl__arch_get_required_paging_memory(unsigned long maxmem_kb, ++ unsigned int smp_cpus); ++ + #if defined(__i386__) || defined(__x86_64__) + + #define LAPIC_BASE_ADDRESS 0xfee00000 +diff --git a/tools/libs/light/libxl_arm.c b/tools/libs/light/libxl_arm.c +index e2901f13b724..d59b464192c2 100644 +--- a/tools/libs/light/libxl_arm.c ++++ b/tools/libs/light/libxl_arm.c +@@ -154,6 +154,18 @@ out: + return rc; + } + ++unsigned long libxl__arch_get_required_paging_memory(unsigned long maxmem_kb, ++ unsigned int smp_cpus) ++{ ++ /* ++ * 256 pages (1MB) per vcpu, ++ * plus 1 page per MiB of RAM for the P2M map, ++ * This is higher than the minimum that Xen would allocate if no value ++ * were given (but the Xen minimum is for safety, not performance). ++ */ ++ return 4 * (256 * smp_cpus + maxmem_kb / 1024); ++} ++ + static struct arch_info { + const char *guest_type; + const char *timer_compat; +diff --git a/tools/libs/light/libxl_utils.c b/tools/libs/light/libxl_utils.c +index 4699c4a0a36f..e276c0ee9cc3 100644 +--- a/tools/libs/light/libxl_utils.c ++++ b/tools/libs/light/libxl_utils.c +@@ -18,6 +18,7 @@ + #include <ctype.h> + + #include "libxl_internal.h" ++#include "libxl_arch.h" + #include "_paths.h" + + #ifndef LIBXL_HAVE_NONCONST_LIBXL_BASENAME_RETURN_VALUE +@@ -39,13 +40,7 @@ char *libxl_basename(const char *name) + + unsigned long libxl_get_required_shadow_memory(unsigned long maxmem_kb, unsigned int smp_cpus) + { +- /* 256 pages (1MB) per vcpu, +- plus 1 page per MiB of RAM for the P2M map, +- plus 1 page per MiB of RAM to shadow the resident processes. +- This is higher than the minimum that Xen would allocate if no value +- were given (but the Xen minimum is for safety, not performance). +- */ +- return 4 * (256 * smp_cpus + 2 * (maxmem_kb / 1024)); ++ return libxl__arch_get_required_paging_memory(maxmem_kb, smp_cpus); + } + + char *libxl_domid_to_name(libxl_ctx *ctx, uint32_t domid) +diff --git a/tools/libs/light/libxl_x86.c b/tools/libs/light/libxl_x86.c +index 18c3c77ccde3..4d66478fe9dd 100644 +--- a/tools/libs/light/libxl_x86.c ++++ b/tools/libs/light/libxl_x86.c +@@ -882,6 +882,19 @@ void libxl__arch_update_domain_config(libxl__gc *gc, + libxl_defbool_val(src->b_info.arch_x86.msr_relaxed)); + } + ++unsigned long libxl__arch_get_required_paging_memory(unsigned long maxmem_kb, ++ unsigned int smp_cpus) ++{ ++ /* ++ * 256 pages (1MB) per vcpu, ++ * plus 1 page per MiB of RAM for the P2M map, ++ * plus 1 page per MiB of RAM to shadow the resident processes. ++ * This is higher than the minimum that Xen would allocate if no value ++ * were given (but the Xen minimum is for safety, not performance). ++ */ ++ return 4 * (256 * smp_cpus + 2 * (maxmem_kb / 1024)); ++} ++ + /* + * Local variables: + * mode: C +-- +2.37.3 + |