Mailing List Archive

From: Paul Durrant <pdurrant@amazon.com>

... sub-operation of XEN_DOMCTL_iommu_ctl.

This patch adds a new sub-operation into the domctl. The code in iommu_ctl()
is extended to call a new arch-specific iommu_set_allocation() function which
will be called with the IOMMU page-table overhead (in 4k pages) in response
to libxl issuing a new domctl via the xc_iommu_set_allocation() helper
function.

The helper function is only called in the x86 implementation of
libxl__arch_domain_create() when the calculated 'iommu_memkb' value is
non-zero. Hence the ARM implementation of iommu_set_allocation() simply
returns -EOPNOTSUPP.

NOTE: The implementation of the IOMMU page-table memory pool will be added in
a subsequent patch and so the x86 implementation of
iommu_set_allocation() currently does nothing other than return 0 (to
indicate success) thereby ensuring that the new call in
libxl__arch_domain_create() always succeeds.

Signed-off-by: Paul Durrant <pdurrant@amazon.com>
---
Cc: Ian Jackson <iwj@xenproject.org>
Cc: Wei Liu <wl@xen.org>
Cc: Andrew Cooper <andrew.cooper3@citrix.com>
Cc: George Dunlap <george.dunlap@citrix.com>
Cc: Jan Beulich <jbeulich@suse.com>
Cc: Julien Grall <julien@xen.org>
Cc: Stefano Stabellini <sstabellini@kernel.org>
Cc: Anthony PERARD <anthony.perard@citrix.com>
Cc: Volodymyr Babchuk <Volodymyr_Babchuk@epam.com>
Cc: "Roger Pau Monné" <roger.pau@citrix.com>
---
tools/libs/ctrl/include/xenctrl.h | 5 +++++
tools/libs/ctrl/xc_domain.c | 16 ++++++++++++++++
tools/libs/light/libxl_x86.c | 10 ++++++++++
xen/drivers/passthrough/iommu.c | 8 ++++++++
xen/drivers/passthrough/x86/iommu.c | 5 +++++
xen/include/asm-arm/iommu.h | 6 ++++++
xen/include/asm-x86/iommu.h | 2 ++
xen/include/public/domctl.h | 8 ++++++++
8 files changed, 60 insertions(+)

diff --git a/tools/libs/ctrl/include/xenctrl.h b/tools/libs/ctrl/include/xenctrl.h
index 3796425e1e..4d6c9d44bc 100644
--- a/tools/libs/ctrl/include/xenctrl.h
+++ b/tools/libs/ctrl/include/xenctrl.h
@@ -2650,6 +2650,11 @@ int xc_livepatch_replace(xc_interface *xch, char *name, uint32_t timeout, uint32
int xc_domain_cacheflush(xc_interface *xch, uint32_t domid,
xen_pfn_t start_pfn, xen_pfn_t nr_pfns);

+/* IOMMU control operations */
+
+int xc_iommu_set_allocation(xc_interface *xch, uint32_t domid,
+ unsigned int nr_pages);
+
/* Compat shims */
#include "xenctrl_compat.h"

diff --git a/tools/libs/ctrl/xc_domain.c b/tools/libs/ctrl/xc_domain.c
index e7cea4a17d..0b20a8f2ee 100644
--- a/tools/libs/ctrl/xc_domain.c
+++ b/tools/libs/ctrl/xc_domain.c
@@ -2185,6 +2185,22 @@ int xc_domain_soft_reset(xc_interface *xch,
domctl.domain = domid;
return do_domctl(xch, &domctl);
}
+
+int xc_iommu_set_allocation(xc_interface *xch, uint32_t domid,
+ unsigned int nr_pages)
+{
+ DECLARE_DOMCTL;
+
+ memset(&domctl, 0, sizeof(domctl));
+
+ domctl.cmd = XEN_DOMCTL_iommu_ctl;
+ domctl.domain = domid;
+ domctl.u.iommu_ctl.op = XEN_DOMCTL_IOMMU_SET_ALLOCATION;
+ domctl.u.iommu_ctl.u.set_allocation.nr_pages = nr_pages;
+
+ return do_domctl(xch, &domctl);
+}
+
/*
* Local variables:
* mode: C
diff --git a/tools/libs/light/libxl_x86.c b/tools/libs/light/libxl_x86.c
index 6ec6c27c83..9631974dd6 100644
--- a/tools/libs/light/libxl_x86.c
+++ b/tools/libs/light/libxl_x86.c
@@ -520,6 +520,16 @@ int libxl__arch_domain_create(libxl__gc *gc, libxl_domain_config *d_config,
NULL, 0, &shadow, 0, NULL);
}

+ if (d_config->b_info.iommu_memkb) {
+ unsigned int nr_pages = DIV_ROUNDUP(d_config->b_info.iommu_memkb, 4);
+
+ ret = xc_iommu_set_allocation(ctx->xch, domid, nr_pages);
+ if (ret) {
+ LOGED(ERROR, domid, "Failed to set IOMMU allocation");
+ goto out;
+ }
+ }
+
if (d_config->c_info.type == LIBXL_DOMAIN_TYPE_PV &&
libxl_defbool_val(d_config->b_info.u.pv.e820_host)) {
ret = libxl__e820_alloc(gc, domid, d_config);
diff --git a/xen/drivers/passthrough/iommu.c b/xen/drivers/passthrough/iommu.c
index bef0405984..642d5c8331 100644
--- a/xen/drivers/passthrough/iommu.c
+++ b/xen/drivers/passthrough/iommu.c
@@ -515,6 +515,14 @@ static int iommu_ctl(

switch ( ctl->op )
{
+ case XEN_DOMCTL_IOMMU_SET_ALLOCATION:
+ {
+ struct xen_domctl_iommu_set_allocation *set_allocation =
+ &ctl->u.set_allocation;
+
+ rc = iommu_set_allocation(d, set_allocation->nr_pages);
+ break;
+ }
default:
rc = -EOPNOTSUPP;
break;
diff --git a/xen/drivers/passthrough/x86/iommu.c b/xen/drivers/passthrough/x86/iommu.c
index f17b1820f4..b168073f10 100644
--- a/xen/drivers/passthrough/x86/iommu.c
+++ b/xen/drivers/passthrough/x86/iommu.c
@@ -134,6 +134,11 @@ void __hwdom_init arch_iommu_check_autotranslated_hwdom(struct domain *d)
panic("PVH hardware domain iommu must be set in 'strict' mode\n");
}

+int iommu_set_allocation(struct domain *d, unsigned nr_pages)
+{
+ return 0;
+}
+
int arch_iommu_domain_init(struct domain *d)
{
struct domain_iommu *hd = dom_iommu(d);
diff --git a/xen/include/asm-arm/iommu.h b/xen/include/asm-arm/iommu.h
index 937edc8373..2e4735bace 100644
--- a/xen/include/asm-arm/iommu.h
+++ b/xen/include/asm-arm/iommu.h
@@ -33,6 +33,12 @@ int __must_check arm_iommu_map_page(struct domain *d, dfn_t dfn, mfn_t mfn,
int __must_check arm_iommu_unmap_page(struct domain *d, dfn_t dfn,
unsigned int *flush_flags);

+static inline int iommu_set_allocation(struct domain *d,
+ unsigned int nr_pages)
+{
+ return -EOPNOTSUPP;
+}
+
#endif /* __ARCH_ARM_IOMMU_H__ */

/*
diff --git a/xen/include/asm-x86/iommu.h b/xen/include/asm-x86/iommu.h
index 970eb06ffa..d086f564af 100644
--- a/xen/include/asm-x86/iommu.h
+++ b/xen/include/asm-x86/iommu.h
@@ -138,6 +138,8 @@ int pi_update_irte(const struct pi_desc *pi_desc, const struct pirq *pirq,
int __must_check iommu_free_pgtables(struct domain *d);
struct page_info *__must_check iommu_alloc_pgtable(struct domain *d);

+int __must_check iommu_set_allocation(struct domain *d, unsigned int nr_pages);
+
#endif /* !__ARCH_X86_IOMMU_H__ */
/*
* Local variables:
diff --git a/xen/include/public/domctl.h b/xen/include/public/domctl.h
index 75e855625a..6402678838 100644
--- a/xen/include/public/domctl.h
+++ b/xen/include/public/domctl.h
@@ -1138,8 +1138,16 @@ struct xen_domctl_vuart_op {

#define XEN_DOMCTL_IOMMU_INVALID 0

+#define XEN_DOMCTL_IOMMU_SET_ALLOCATION 1
+struct xen_domctl_iommu_set_allocation {
+ uint32_t nr_pages;
+};
+
struct xen_domctl_iommu_ctl {
uint32_t op; /* XEN_DOMCTL_IOMMU_* */
+ union {
+ struct xen_domctl_iommu_set_allocation set_allocation;
+ } u;
};

struct xen_domctl {
--
2.20.1