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[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] [Xen-changelog] [xen stable-4.10] xen/pvshim: add shim_mem cmdline parameter
commit 7dcc20e0c8cf6fa30f483b0c91c8566a97a61031
Author: Sergey Dyasli <sergey.dyasli@xxxxxxxxxx>
AuthorDate: Thu Jan 11 11:41:20 2018 +0000
Commit: Roger Pau Monne <roger.pau@xxxxxxxxxx>
CommitDate: Fri Jan 12 15:47:32 2018 +0000
xen/pvshim: add shim_mem cmdline parameter
Signed-off-by: Sergey Dyasli <sergey.dyasli@xxxxxxxxxx>
---
docs/misc/xen-command-line.markdown | 16 +++++++++++++
xen/arch/x86/dom0_build.c | 18 ++++++++++++++-
xen/arch/x86/pv/shim.c | 46 +++++++++++++++++++++++++++++++++++++
xen/include/asm-x86/pv/shim.h | 6 +++++
4 files changed, 85 insertions(+), 1 deletion(-)
diff --git a/docs/misc/xen-command-line.markdown
b/docs/misc/xen-command-line.markdown
index 3a1a9c1fba..9f51710a46 100644
--- a/docs/misc/xen-command-line.markdown
+++ b/docs/misc/xen-command-line.markdown
@@ -686,6 +686,8 @@ any dom0 autoballooning feature present in your toolstack.
See the
_xl.conf(5)_ man page or [Xen Best
Practices](http://wiki.xen.org/wiki/Xen_Best_Practices#Xen_dom0_dedicated_memory_and_preventing_dom0_memory_ballooning).
+This option doesn't have effect if pv-shim mode is enabled.
+
### dom0\_nodes
> `= List of [ <integer> | relaxed | strict ]`
@@ -1456,6 +1458,20 @@ guest compatibly inside an HVM container.
In this mode, the kernel and initrd passed as modules to the hypervisor are
constructed into a plain unprivileged PV domain.
+### shim\_mem (x86)
+> `= List of ( min:<size> | max:<size> | <size> )`
+
+Set the amount of memory that xen-shim reserves for itself. Only has effect
+if pv-shim mode is enabled.
+
+* `min:<size>` specifies the minimum amount of memory. Ignored if greater
+ than max. Default: 10M.
+* `max:<size>` specifies the maximum amount of memory. Default: 128M.
+* `<size>` specifies the exact amount of memory. Overrides both min and max.
+
+By default, 1/16th of total HVM container's memory is reserved for xen-shim
+with minimum amount being 10MB and maximum amount 128MB.
+
### rcu-idle-timer-period-ms
> `= <integer>`
diff --git a/xen/arch/x86/dom0_build.c b/xen/arch/x86/dom0_build.c
index 452298c624..bc713fb2b5 100644
--- a/xen/arch/x86/dom0_build.c
+++ b/xen/arch/x86/dom0_build.c
@@ -51,6 +51,13 @@ static long __init parse_amt(const char *s, const char **ps)
static int __init parse_dom0_mem(const char *s)
{
+ /* xen-shim uses shim_mem parameter instead of dom0_mem */
+ if ( pv_shim )
+ {
+ printk("Ignoring dom0_mem param in pv-shim mode\n");
+ return 0;
+ }
+
do {
if ( !strncmp(s, "min:", 4) )
dom0_min_nrpages = parse_amt(s+4, &s);
@@ -284,7 +291,16 @@ unsigned long __init dom0_compute_nr_pages(
* maximum of 128MB.
*/
if ( nr_pages == 0 )
- nr_pages = -min(avail / 16, 128UL << (20 - PAGE_SHIFT));
+ {
+ uint64_t rsvd = min(avail / 16, 128UL << (20 - PAGE_SHIFT));
+ if ( pv_shim )
+ {
+ rsvd = pv_shim_mem(avail);
+ printk("Reserved %lu pages for xen-shim\n", rsvd);
+
+ }
+ nr_pages = -rsvd;
+ }
/* Negative specification means "all memory - specified amount". */
if ( (long)nr_pages < 0 ) nr_pages += avail;
diff --git a/xen/arch/x86/pv/shim.c b/xen/arch/x86/pv/shim.c
index c53a4ca407..6dc1ee45d7 100644
--- a/xen/arch/x86/pv/shim.c
+++ b/xen/arch/x86/pv/shim.c
@@ -53,6 +53,52 @@ static long pv_shim_grant_table_op(unsigned int cmd,
XEN_GUEST_HANDLE_PARAM(void) uop,
unsigned int count);
+/*
+ * By default, 1/16th of total HVM container's memory is reserved for xen-shim
+ * with minimum amount being 10MB and maximum amount 128MB. Some users may wish
+ * to tune this constants for better memory utilization. This can be achieved
+ * using the following xen-shim's command line option:
+ *
+ * shim_mem=[min:<min_amt>,][max:<max_amt>,][<amt>]
+ *
+ * <min_amt>: The minimum amount of memory that should be allocated for
xen-shim
+ * (ignored if greater than max)
+ * <max_amt>: The maximum amount of memory that should be allocated for
xen-shim
+ * <amt>: The precise amount of memory to allocate for xen-shim
+ * (overrides both min and max)
+ */
+static uint64_t __initdata shim_nrpages;
+static uint64_t __initdata shim_min_nrpages = 10UL << (20 - PAGE_SHIFT);
+static uint64_t __initdata shim_max_nrpages = 128UL << (20 - PAGE_SHIFT);
+
+static int __init parse_shim_mem(const char *s)
+{
+ do {
+ if ( !strncmp(s, "min:", 4) )
+ shim_min_nrpages = parse_size_and_unit(s+4, &s) >> PAGE_SHIFT;
+ else if ( !strncmp(s, "max:", 4) )
+ shim_max_nrpages = parse_size_and_unit(s+4, &s) >> PAGE_SHIFT;
+ else
+ shim_nrpages = parse_size_and_unit(s, &s) >> PAGE_SHIFT;
+ } while ( *s++ == ',' );
+
+ return s[-1] ? -EINVAL : 0;
+}
+custom_param("shim_mem", parse_shim_mem);
+
+uint64_t pv_shim_mem(uint64_t avail)
+{
+ uint64_t rsvd = min(avail / 16, shim_max_nrpages);
+
+ if ( shim_nrpages )
+ return shim_nrpages;
+
+ if ( shim_min_nrpages <= shim_max_nrpages )
+ rsvd = max(rsvd, shim_min_nrpages);
+
+ return rsvd;
+}
+
#define L1_PROT (_PAGE_PRESENT|_PAGE_RW|_PAGE_ACCESSED|_PAGE_USER| \
_PAGE_GUEST_KERNEL)
#define COMPAT_L1_PROT (_PAGE_PRESENT|_PAGE_RW|_PAGE_ACCESSED)
diff --git a/xen/include/asm-x86/pv/shim.h b/xen/include/asm-x86/pv/shim.h
index 4d5f0b43fc..0ef452158e 100644
--- a/xen/include/asm-x86/pv/shim.h
+++ b/xen/include/asm-x86/pv/shim.h
@@ -38,6 +38,7 @@ void pv_shim_setup_dom(struct domain *d, l4_pgentry_t
*l4start,
int pv_shim_shutdown(uint8_t reason);
void pv_shim_inject_evtchn(unsigned int port);
domid_t get_initial_domain_id(void);
+uint64_t pv_shim_mem(uint64_t avail);
#else
@@ -63,6 +64,11 @@ static inline domid_t get_initial_domain_id(void)
{
return 0;
}
+static inline uint64_t pv_shim_mem(uint64_t avail)
+{
+ ASSERT_UNREACHABLE();
+ return 0;
+}
#endif
--
generated by git-patchbot for /home/xen/git/xen.git#stable-4.10
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