On 2/14/22 15:41, Igor Mammedov wrote: > On Mon, 14 Feb 2022 15:18:43 +0000 > Joao Martins <joao.m.mart...@oracle.com> wrote: >> On 2/14/22 15:03, Igor Mammedov wrote: >>> On Mon, 7 Feb 2022 20:24:21 +0000 >>> Joao Martins <joao.m.mart...@oracle.com> wrote: >>>> diff --git a/hw/i386/pc.c b/hw/i386/pc.c >>>> index b060aedd38f3..f8712eb8427e 100644 >>>> --- a/hw/i386/pc.c >>>> +++ b/hw/i386/pc.c >>>> @@ -842,6 +842,7 @@ static void relocate_4g(MachineState *machine, >>>> PCMachineState *pcms) >>>> X86MachineState *x86ms = X86_MACHINE(pcms); >>>> ram_addr_t device_mem_size = 0; >>>> uint32_t eax, vendor[3]; >>>> + hwaddr maxphysaddr; >>>> >>>> host_cpuid(0x0, 0, &eax, &vendor[0], &vendor[2], &vendor[1]); >>>> if (!IS_AMD_VENDOR(vendor)) { >>>> @@ -858,6 +859,12 @@ static void relocate_4g(MachineState *machine, >>>> PCMachineState *pcms) >>>> return; >>>> } >>>> >>>> + maxphysaddr = ((hwaddr)1 << X86_CPU(first_cpu)->phys_bits) - 1; >>>> + if (maxphysaddr < AMD_ABOVE_1TB_START) >>>> + warn_report("Relocated RAM above 4G to start at %lu " >>>> + "phys-bits too low (%u)", >>>> + AMD_ABOVE_1TB_START, X86_CPU(first_cpu)->phys_bits); >>> >>> perhaps this hunk belongs to the end of pc_memory_init(), >>> it's not HT fixup specific at all? >>> >> It is HT fixup related. Because we are relocating the whole above-4g-ram, >> on what used to be enough with just 40 phys bits (default). > > what if user starts QEMU with amount of RAM that won't fit into > configured phys bits (whether it's default one or one that comes from host) > and not on AMD host at that so no relocation happens but we still have > broken configuration. What matters here is the end address that might > be used by guest (pci64_bit hole end) is reachable. > > That's why I suggested to make it generic check instead of AMD specific one. > OK, I see.
If I'm being dense, that would require replacing AMD_ABOVE_1TB_START in the comparison to something that computes the max used addr -- Let me try that then.