[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] [PATCH] xen/arm: Avoid to open-code the relinquish state machine
In commit 0dfffe01d5 "x86: Improve the efficiency of domain_relinquish_resources()", the x86 version of the function has been reworked to avoid open-coding the state machine and also add more documentation. Bring the Arm version on part with x86 by introducing a documented PROGRESS() macro to avoid latent bugs and make the new PROG_* states private to domain_relinquish_resources(). Cc: Andrew Cooper <andrew.cooper3@xxxxxxxxxx> Signed-off-by: Julien Grall <jgrall@xxxxxxxxxx> --- xen/arch/arm/domain.c | 60 ++++++++++++++++++++++-------------- xen/include/asm-arm/domain.h | 9 +----- 2 files changed, 38 insertions(+), 31 deletions(-) diff --git a/xen/arch/arm/domain.c b/xen/arch/arm/domain.c index 6627be2922..31169326b2 100644 --- a/xen/arch/arm/domain.c +++ b/xen/arch/arm/domain.c @@ -674,7 +674,6 @@ int arch_domain_create(struct domain *d, int rc, count = 0; BUILD_BUG_ON(GUEST_MAX_VCPUS < MAX_VIRT_CPUS); - d->arch.relmem = RELMEM_not_started; /* Idle domains do not need this setup */ if ( is_idle_domain(d) ) @@ -950,13 +949,41 @@ static int relinquish_memory(struct domain *d, struct page_list_head *list) return ret; } +/* + * Record the current progress. Subsequent hypercall continuations will + * logically restart work from this point. + * + * PROGRESS() markers must not be in the middle of loops. The loop + * variable isn't preserved accross a continuation. + * + * To avoid redundant work, there should be a marker before each + * function which may return -ERESTART. + */ +enum { + PROG_tee = 1, + PROG_xen, + PROG_page, + PROG_mapping, + PROG_done, +}; + +#define PROGRESS(x) \ + d->arch.rel_priv = PROG_ ## x; \ + /* Fallthrough */ \ + case PROG_ ## x + int domain_relinquish_resources(struct domain *d) { int ret = 0; - switch ( d->arch.relmem ) + /* + * This hypercall can take minutes of wallclock time to complete. This + * logic implements a co-routine, stashing state in struct domain across + * hypercall continuation boundaries. + */ + switch ( d->arch.rel_priv ) { - case RELMEM_not_started: + case 0: ret = iommu_release_dt_devices(d); if ( ret ) return ret; @@ -967,42 +994,27 @@ int domain_relinquish_resources(struct domain *d) */ domain_vpl011_deinit(d); - d->arch.relmem = RELMEM_tee; - /* Fallthrough */ - - case RELMEM_tee: + PROGRESS(tee): ret = tee_relinquish_resources(d); if (ret ) return ret; - d->arch.relmem = RELMEM_xen; - /* Fallthrough */ - - case RELMEM_xen: + PROGRESS(xen): ret = relinquish_memory(d, &d->xenpage_list); if ( ret ) return ret; - d->arch.relmem = RELMEM_page; - /* Fallthrough */ - - case RELMEM_page: + PROGRESS(page): ret = relinquish_memory(d, &d->page_list); if ( ret ) return ret; - d->arch.relmem = RELMEM_mapping; - /* Fallthrough */ - - case RELMEM_mapping: + PROGRESS(mapping): ret = relinquish_p2m_mapping(d); if ( ret ) return ret; - d->arch.relmem = RELMEM_done; - /* Fallthrough */ - - case RELMEM_done: + PROGRESS(done): break; default: @@ -1012,6 +1024,8 @@ int domain_relinquish_resources(struct domain *d) return 0; } +#undef PROGRESS + void arch_dump_domain_info(struct domain *d) { p2m_dump_info(d); diff --git a/xen/include/asm-arm/domain.h b/xen/include/asm-arm/domain.h index d39477a939..d2142c6707 100644 --- a/xen/include/asm-arm/domain.h +++ b/xen/include/asm-arm/domain.h @@ -56,14 +56,7 @@ struct arch_domain struct vmmio vmmio; /* Continuable domain_relinquish_resources(). */ - enum { - RELMEM_not_started, - RELMEM_tee, - RELMEM_xen, - RELMEM_page, - RELMEM_mapping, - RELMEM_done, - } relmem; + unsigned int rel_priv; struct { uint64_t offset; -- 2.17.1
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