Messages in this thread | | | Date | Thu, 16 Feb 2023 09:24:45 -0800 | Subject | Re: [PATCH v10 12/26] gunyah: vm_mgr: Add/remove user memory regions | From | Elliot Berman <> |
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On 2/15/2023 10:38 PM, Greg Kroah-Hartman wrote: > On Tue, Feb 14, 2023 at 01:24:16PM -0800, Elliot Berman wrote: >> >> When launching a virtual machine, Gunyah userspace allocates memory for >> the guest and informs Gunyah about these memory regions through >> SET_USER_MEMORY_REGION ioctl. > > It also frees memory, see below. Why not document that? >
I can mention in commit text, too.
>> + case GH_VM_SET_USER_MEM_REGION: { >> + struct gh_userspace_memory_region region; >> + >> + if (copy_from_user(®ion, argp, sizeof(region))) >> + return -EFAULT; >> + >> + /* All other flag bits are reserved for future use */ >> + if (region.flags & ~(GH_MEM_ALLOW_READ | GH_MEM_ALLOW_WRITE | GH_MEM_ALLOW_EXEC | >> + GH_MEM_LENT)) >> + return -EINVAL; > > Nice, thanks for validating that. > > >> + >> + > > Nit, 2 blank lines are not needed :( > > >> + if (region.memory_size) >> + r = gh_vm_mem_alloc(ghvm, ®ion); >> + else >> + r = gh_vm_mem_free(ghvm, region.label); > > So if you set the size to 0 it is freed? Wouldn't a separate ioctl make > more sense? Where is this logic documented to userspace? >
We're following KVM convention here. The logic is documented in patch 17/26.
Thanks, Elliot
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