From b6bfee023b15f25c1db077df7bfd2e9212cda762 Mon Sep 17 00:00:00 2001 From: Gerd Hoffmann Date: Mon, 18 Mar 2024 16:53:36 +0100 Subject: [PATCH 1/2] target/i386: add guest-phys-bits cpu property commit 513ba32dccc659c80722b3a43233b26eaa50309a upstream. Allows to set guest-phys-bits (cpuid leaf 80000008, eax[23:16]) via -cpu $model,guest-phys-bits=$nr. Intel-SIG: commit 513ba32dccc6 target/i386: add guest-phys-bits cpu property Signed-off-by: Gerd Hoffmann Message-ID: <20240318155336.156197-3-kraxel@redhat.com> Reviewed-by: Zhao Liu Signed-off-by: Paolo Bonzini [jz: compatible property for 9.0 machines not included] Signed-off-by: Jason Zeng --- target/i386/cpu.c | 22 ++++++++++++++++++++++ target/i386/cpu.h | 8 ++++++++ 2 files changed, 30 insertions(+) diff --git a/target/i386/cpu.c b/target/i386/cpu.c index ca7e5337b0..93f88b7bf8 100644 --- a/target/i386/cpu.c +++ b/target/i386/cpu.c @@ -6827,6 +6827,7 @@ void cpu_x86_cpuid(CPUX86State *env, uint32_t index, uint32_t count, if (env->features[FEAT_8000_0001_EDX] & CPUID_EXT2_LM) { /* 64 bit processor */ *eax |= (cpu_x86_virtual_addr_width(env) << 8); + *eax |= (cpu->guest_phys_bits << 16); } *ebx = env->features[FEAT_8000_0008_EBX]; if (cs->nr_cores * cs->nr_threads > 1) { @@ -7603,6 +7604,14 @@ static void x86_cpu_realizefn(DeviceState *dev, Error **errp) goto out; } + if (cpu->guest_phys_bits == -1) { + /* + * If it was not set by the user, or by the accelerator via + * cpu_exec_realizefn, clear. + */ + cpu->guest_phys_bits = 0; + } + if (cpu->ucode_rev == 0) { /* * The default is the same as KVM's. Note that this check @@ -7653,6 +7662,14 @@ static void x86_cpu_realizefn(DeviceState *dev, Error **errp) if (cpu->phys_bits == 0) { cpu->phys_bits = TCG_PHYS_ADDR_BITS; } + if (cpu->guest_phys_bits && + (cpu->guest_phys_bits > cpu->phys_bits || + cpu->guest_phys_bits < 32)) { + error_setg(errp, "guest-phys-bits should be between 32 and %u " + " (but is %u)", + cpu->phys_bits, cpu->guest_phys_bits); + return; + } } else { /* For 32 bit systems don't use the user set value, but keep * phys_bits consistent with what we tell the guest. @@ -7661,6 +7678,10 @@ static void x86_cpu_realizefn(DeviceState *dev, Error **errp) error_setg(errp, "phys-bits is not user-configurable in 32 bit"); return; } + if (cpu->guest_phys_bits != 0) { + error_setg(errp, "guest-phys-bits is not user-configurable in 32 bit"); + return; + } if (env->features[FEAT_1_EDX] & (CPUID_PSE36 | CPUID_PAE)) { cpu->phys_bits = 36; @@ -8167,6 +8188,7 @@ static Property x86_cpu_properties[] = { DEFINE_PROP_BOOL("x-force-features", X86CPU, force_features, false), DEFINE_PROP_BOOL("kvm", X86CPU, expose_kvm, true), DEFINE_PROP_UINT32("phys-bits", X86CPU, phys_bits, 0), + DEFINE_PROP_UINT32("guest-phys-bits", X86CPU, guest_phys_bits, -1), DEFINE_PROP_BOOL("host-phys-bits", X86CPU, host_phys_bits, false), DEFINE_PROP_UINT8("host-phys-bits-limit", X86CPU, host_phys_bits_limit, 0), DEFINE_PROP_BOOL("fill-mtrr-mask", X86CPU, fill_mtrr_mask, false), diff --git a/target/i386/cpu.h b/target/i386/cpu.h index 34f9615b98..d6fdcc04ca 100644 --- a/target/i386/cpu.h +++ b/target/i386/cpu.h @@ -2029,6 +2029,14 @@ struct ArchCPU { /* Number of physical address bits supported */ uint32_t phys_bits; + /* + * Number of guest physical address bits available. Usually this is + * identical to host physical address bits. With NPT or EPT 4-level + * paging, guest physical address space might be restricted to 48 bits + * even if the host cpu supports more physical address bits. + */ + uint32_t guest_phys_bits; + /* in order to simplify APIC support, we leave this pointer to the user */ struct DeviceState *apic_state; -- Gitee From a2383a2a0537750794223f21156241b1b1e78d2e Mon Sep 17 00:00:00 2001 From: Gerd Hoffmann Date: Mon, 18 Mar 2024 16:53:35 +0100 Subject: [PATCH 2/2] kvm: add support for guest physical bits commit 0d08c423688edcca857f88dab20f1fc56de2b281 upstream. Query kvm for supported guest physical address bits, in cpuid function 80000008, eax[23:16]. Usually this is identical to host physical address bits. With NPT or EPT being used this might be restricted to 48 (max 4-level paging address space size) even if the host cpu supports more physical address bits. When set pass this to the guest, using cpuid too. Guest firmware can use this to figure how big the usable guest physical address space is, so PCI bar mapping are actually reachable. Intel-SIG: commit 0d08c423688e kvm: add support for guest physical bits Signed-off-by: Gerd Hoffmann Reviewed-by: Xiaoyao Li Reviewed-by: Zhao Liu Message-ID: <20240318155336.156197-2-kraxel@redhat.com> Signed-off-by: Paolo Bonzini Signed-off-by: Jason Zeng --- target/i386/kvm/kvm-cpu.c | 50 ++++++++++++++++++++++++++++++++------- 1 file changed, 42 insertions(+), 8 deletions(-) diff --git a/target/i386/kvm/kvm-cpu.c b/target/i386/kvm/kvm-cpu.c index 9c791b7b05..f76972e47e 100644 --- a/target/i386/kvm/kvm-cpu.c +++ b/target/i386/kvm/kvm-cpu.c @@ -18,10 +18,32 @@ #include "kvm_i386.h" #include "hw/core/accel-cpu.h" +static void kvm_set_guest_phys_bits(CPUState *cs) +{ + X86CPU *cpu = X86_CPU(cs); + uint32_t eax, guest_phys_bits; + + eax = kvm_arch_get_supported_cpuid(cs->kvm_state, 0x80000008, 0, R_EAX); + guest_phys_bits = (eax >> 16) & 0xff; + if (!guest_phys_bits) { + return; + } + cpu->guest_phys_bits = guest_phys_bits; + if (cpu->guest_phys_bits > cpu->phys_bits) { + cpu->guest_phys_bits = cpu->phys_bits; + } + + if (cpu->host_phys_bits && cpu->host_phys_bits_limit && + cpu->guest_phys_bits > cpu->host_phys_bits_limit) { + cpu->guest_phys_bits = cpu->host_phys_bits_limit; + } +} + static bool kvm_cpu_realizefn(CPUState *cs, Error **errp) { X86CPU *cpu = X86_CPU(cs); CPUX86State *env = &cpu->env; + bool ret; /* * The realize order is important, since x86_cpu_realize() checks if @@ -32,13 +54,15 @@ static bool kvm_cpu_realizefn(CPUState *cs, Error **errp) * * realize order: * - * x86_cpu_realize(): - * -> x86_cpu_expand_features() - * -> cpu_exec_realizefn(): - * -> accel_cpu_common_realize() - * kvm_cpu_realizefn() -> host_cpu_realizefn() - * -> cpu_common_realizefn() - * -> check/update ucode_rev, phys_bits, mwait + * x86_cpu_realizefn(): + * x86_cpu_expand_features() + * cpu_exec_realizefn(): + * accel_cpu_common_realize() + * kvm_cpu_realizefn() + * host_cpu_realizefn() + * kvm_set_guest_phys_bits() + * check/update ucode_rev, phys_bits, guest_phys_bits, mwait + * cpu_common_realizefn() (via xcc->parent_realize) */ if (cpu->max_features) { if (enable_cpu_pm && kvm_has_waitpkg()) { @@ -50,7 +74,17 @@ static bool kvm_cpu_realizefn(CPUState *cs, Error **errp) MSR_IA32_UCODE_REV); } } - return host_cpu_realizefn(cs, errp); + ret = host_cpu_realizefn(cs, errp); + if (!ret) { + return ret; + } + + if ((env->features[FEAT_8000_0001_EDX] & CPUID_EXT2_LM) && + cpu->guest_phys_bits == -1) { + kvm_set_guest_phys_bits(cs); + } + + return true; } static bool lmce_supported(void) -- Gitee