On 8/7/24 5:45 PM, Christoph Schlameuss wrote:
Add a test case verifying basic running and interaction of ucontrol VMs.
Fill the segment and page tables for allocated memory and map memory on
first access.
* uc_map_unmap
Store and load data to mapped and unmapped memory and use pic segment
translation handling to map memory on access.
Signed-off-by: Christoph Schlameuss <schlameuss@xxxxxxxxxxxxx>
---
.../selftests/kvm/s390x/ucontrol_test.c | 167 +++++++++++++++++-
1 file changed, 166 insertions(+), 1 deletion(-)
[...]
+static void init_st_pt(FIXTURE_DATA(uc_kvm) * self)
+{
+ struct kvm_sync_regs *sync_regs = &self->run->s.regs;
+ u64 first_pt_addr, ste, s_addr, pte;
+ struct kvm_run *run = self->run;
+ void *se_addr;
+ int si, pi;
+ u64 *phd;
+
+ /* set PASCE addr */
+ self->pgd = self->base_gpa + SZ_1M;
+ phd = gpa2hva(self, self->pgd);
+ memset(phd, 0xff, VM_MEM_TABLE_SIZE);
+
+ first_pt_addr = self->pgd + (VM_MEM_TABLE_SIZE * VM_MEM_MAX_M);
+ /* for each segment in the VM */
+ for (si = 0; si < VM_MEM_MAX_M; si++) {
+ /* build segment table entry (ste) */
+ ste = (first_pt_addr + (VM_MEM_TABLE_SIZE * si)) & ~0x7fful;
+ /* store ste in st */
+ phd[si] = ste;
+
+ se_addr = gpa2hva(self, phd[si]);
+ s_addr = self->base_gpa + (si * SZ_1M);
+ memset(se_addr, 0xff, VM_MEM_TABLE_SIZE);
+ /* for each page in the segment (VM) */
+ for (pi = 0; pi < (SZ_1M / PAGE_SIZE); pi++) {
+ /* build page table entry (pte) */
+ pte = (s_addr + (pi * PAGE_SIZE)) & ~0xffful;
+ /* store pte in pt */
+ ((u64 *)se_addr)[pi] = pte;
+ }
+ }
+ pr_debug("segment table entry %p (0x%lx) --> %p\n",
+ phd, phd[0], gpa2hva(self, (phd[0] & ~0x7fful)));
+ print_hex_bytes("st", (u64)phd, 64);
+ print_hex_bytes("pt", (u64)gpa2hva(self, phd[0]), 128);
+
+ /* PASCE TT=00 for segment table */
+ sync_regs->crs[1] = self->pgd | 0x3;
+ run->kvm_dirty_regs |= KVM_SYNC_CRS;
+}
Having a closer look at this I don't understand why we need to setup DAT
in the guest. Also, the guest's memory easily fits in a couple of
segment entries so you could set the table length TL in the ASCE to one
page instead of 4.
