On 2/16/26 3:57 PM, Jan Beulich wrote:
On 12.02.2026 17:21, Oleksii Kurochko wrote:
--- /dev/null
+++ b/xen/arch/riscv/guestcopy.c
@@ -0,0 +1,112 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+
+#include <xen/domain_page.h>
+#include <xen/page-size.h>
+#include <xen/sched.h>
+#include <xen/string.h>
+
+#include <asm/guest_access.h>
+
+#define COPY_from_guest (0U << 0)
+#define COPY_to_guest (1U << 0)
+#define COPY_ipa (0U << 1)
Like already asked elsewhere - is "ipa" a term commonly in use on RISC-V?
To me it's Arm terminology, which you don't want to copy as is.
As we discussed in another patch thread, IPA isn't really used for RISC-V
and I will rename it to GPA.
Also, don't you prefer to use BIT() everywhere else?
Yes, BIT() would be better for consistency.
+#define COPY_linear (1U << 1)
+
+typedef union
+{
+ struct
+ {
+ struct vcpu *v;
+ } gva;
+
+ struct
+ {
+ struct domain *d;
+ } gpa;
+} copy_info_t;
+
+#define GVA_INFO(vcpu) ((copy_info_t) { .gva = { vcpu } })
+#define GPA_INFO(domain) ((copy_info_t) { .gpa = { domain } })
+
+static struct page_info *translate_get_page(copy_info_t info, uint64_t addr,
The caller has to pass in a domain here. I therefore recommend against
use of copy_info_t for this function. Or wait, this is misleading, as
the consuming part ...
+ bool linear, bool write)
+{
+ p2m_type_t p2mt;
+ struct page_info *page;
+
+ if ( linear )
+ BUG_ON("unimplemeted\n");
... of "linear" is missing here.
Yes, for this once cases it will be used vcpu as an argument passed by "copy_info_t
info".
I will add the comment above suggested below BUG_ON(linear).
Btw, I think it makes sense to change linear to GVA to be more close to RISC-V
spec?
In any event, this one please shorter as:
BUG_ON(linear);
+ page = get_page_from_gfn(info.gpa.d, paddr_to_pfn(addr), &p2mt, P2M_ALLOC);
+
+ if ( !page )
+ return NULL;
+
+ if ( !p2m_is_ram(p2mt) )
+ {
+ put_page(page);
+ return NULL;
+ }
+
+ return page;
+}
The "write" function parameter also is unused, but there's no BUG_ON() for
that one? Imo the p2m_is_ram() check isn't thorough enough (on the Arm
original): p2m_ram_ro shouldn't be allowed when "write" is true. As soon
as you gain p2m_ram_ro on RISC-V, things will need updating here as well.
Perhaps best to leave a note.
I will apply your changes from suggested for Arm patch (Arm: tighten
translate_get_page()) so write will be used and also no extra updates will
be needed here.
+static unsigned long copy_guest(void *buf, uint64_t addr, unsigned int len,
+ copy_info_t info, unsigned int flags)
Why an "unsigned long" return value when ...
+{
+ unsigned int offset = PAGE_OFFSET(addr);
+
+ BUILD_BUG_ON((sizeof(addr)) < sizeof(vaddr_t));
+ BUILD_BUG_ON((sizeof(addr)) < sizeof(paddr_t));
+
+ while ( len )
+ {
+ void *p;
+ unsigned int size = min(len, (unsigned int)PAGE_SIZE - offset);
+ struct page_info *page;
+
+ page = translate_get_page(info, addr, flags & COPY_linear,
+ flags & COPY_to_guest);
+ if ( page == NULL )
+ return len;
... only an "unsigned int" (or 0 further down) is returned? Same
question for copy_to_guest_phys() below then.
Agree, unsigned int should be enough.
+ p = __map_domain_page(page);
+ p += offset;
+ if ( flags & COPY_to_guest )
+ {
+ /*
+ * buf will be NULL when the caller request to zero the
+ * guest memory.
+ */
+ if ( buf )
+ memcpy(p, buf, size);
+ else
+ memset(p, 0, size);
+ }
+ else
+ memcpy(buf, p, size);
+
+ unmap_domain_page(p - offset);
+ put_page(page);
+ len -= size;
+ buf += size;
+ addr += size;
+
+ /*
+ * After the first iteration, guest virtual address is correctly
+ * aligned to PAGE_SIZE.
+ */
+ offset = 0;
+ }
+
+ return 0;
+}
+
+unsigned long copy_to_guest_phys(struct domain *d,
+ paddr_t gpa,
+ void *buf,
+ unsigned int len)
May I suggest to make good use of line length, just like how copy_guest()
does?
Sure, I will do that.
Thanks.
~ Oleksii
