[PATCH v3 22/26] KVM: SVM: Move svm_hardware_setup() and its helpers below svm_x86_ops

From: Sean Christopherson
Date: Tue Dec 07 2021 - 20:56:07 EST


Move svm_hardware_setup() below svm_x86_ops so that KVM can modify ops
during setup, e.g. the vcpu_(un)blocking hooks can be nullified if AVIC
is disabled or unsupported.

No functional change intended.

Signed-off-by: Sean Christopherson <seanjc@xxxxxxxxxx>
---
arch/x86/kvm/svm/svm.c | 466 ++++++++++++++++++++---------------------
1 file changed, 233 insertions(+), 233 deletions(-)

diff --git a/arch/x86/kvm/svm/svm.c b/arch/x86/kvm/svm/svm.c
index dde0106ffc47..98f7c454a784 100644
--- a/arch/x86/kvm/svm/svm.c
+++ b/arch/x86/kvm/svm/svm.c
@@ -873,47 +873,6 @@ static void shrink_ple_window(struct kvm_vcpu *vcpu)
}
}

-/*
- * The default MMIO mask is a single bit (excluding the present bit),
- * which could conflict with the memory encryption bit. Check for
- * memory encryption support and override the default MMIO mask if
- * memory encryption is enabled.
- */
-static __init void svm_adjust_mmio_mask(void)
-{
- unsigned int enc_bit, mask_bit;
- u64 msr, mask;
-
- /* If there is no memory encryption support, use existing mask */
- if (cpuid_eax(0x80000000) < 0x8000001f)
- return;
-
- /* If memory encryption is not enabled, use existing mask */
- rdmsrl(MSR_AMD64_SYSCFG, msr);
- if (!(msr & MSR_AMD64_SYSCFG_MEM_ENCRYPT))
- return;
-
- enc_bit = cpuid_ebx(0x8000001f) & 0x3f;
- mask_bit = boot_cpu_data.x86_phys_bits;
-
- /* Increment the mask bit if it is the same as the encryption bit */
- if (enc_bit == mask_bit)
- mask_bit++;
-
- /*
- * If the mask bit location is below 52, then some bits above the
- * physical addressing limit will always be reserved, so use the
- * rsvd_bits() function to generate the mask. This mask, along with
- * the present bit, will be used to generate a page fault with
- * PFER.RSV = 1.
- *
- * If the mask bit location is 52 (or above), then clear the mask.
- */
- mask = (mask_bit < 52) ? rsvd_bits(mask_bit, 51) | PT_PRESENT_MASK : 0;
-
- kvm_mmu_set_mmio_spte_mask(mask, mask, PT_WRITABLE_MASK | PT_USER_MASK);
-}
-
static void svm_hardware_teardown(void)
{
int cpu;
@@ -928,198 +887,6 @@ static void svm_hardware_teardown(void)
iopm_base = 0;
}

-static __init void svm_set_cpu_caps(void)
-{
- kvm_set_cpu_caps();
-
- supported_xss = 0;
-
- /* CPUID 0x80000001 and 0x8000000A (SVM features) */
- if (nested) {
- kvm_cpu_cap_set(X86_FEATURE_SVM);
-
- if (nrips)
- kvm_cpu_cap_set(X86_FEATURE_NRIPS);
-
- if (npt_enabled)
- kvm_cpu_cap_set(X86_FEATURE_NPT);
-
- if (tsc_scaling)
- kvm_cpu_cap_set(X86_FEATURE_TSCRATEMSR);
-
- /* Nested VM can receive #VMEXIT instead of triggering #GP */
- kvm_cpu_cap_set(X86_FEATURE_SVME_ADDR_CHK);
- }
-
- /* CPUID 0x80000008 */
- if (boot_cpu_has(X86_FEATURE_LS_CFG_SSBD) ||
- boot_cpu_has(X86_FEATURE_AMD_SSBD))
- kvm_cpu_cap_set(X86_FEATURE_VIRT_SSBD);
-
- /* AMD PMU PERFCTR_CORE CPUID */
- if (pmu && boot_cpu_has(X86_FEATURE_PERFCTR_CORE))
- kvm_cpu_cap_set(X86_FEATURE_PERFCTR_CORE);
-
- /* CPUID 0x8000001F (SME/SEV features) */
- sev_set_cpu_caps();
-}
-
-static __init int svm_hardware_setup(void)
-{
- int cpu;
- struct page *iopm_pages;
- void *iopm_va;
- int r;
- unsigned int order = get_order(IOPM_SIZE);
-
- /*
- * NX is required for shadow paging and for NPT if the NX huge pages
- * mitigation is enabled.
- */
- if (!boot_cpu_has(X86_FEATURE_NX)) {
- pr_err_ratelimited("NX (Execute Disable) not supported\n");
- return -EOPNOTSUPP;
- }
- kvm_enable_efer_bits(EFER_NX);
-
- iopm_pages = alloc_pages(GFP_KERNEL, order);
-
- if (!iopm_pages)
- return -ENOMEM;
-
- iopm_va = page_address(iopm_pages);
- memset(iopm_va, 0xff, PAGE_SIZE * (1 << order));
- iopm_base = page_to_pfn(iopm_pages) << PAGE_SHIFT;
-
- init_msrpm_offsets();
-
- supported_xcr0 &= ~(XFEATURE_MASK_BNDREGS | XFEATURE_MASK_BNDCSR);
-
- if (boot_cpu_has(X86_FEATURE_FXSR_OPT))
- kvm_enable_efer_bits(EFER_FFXSR);
-
- if (tsc_scaling) {
- if (!boot_cpu_has(X86_FEATURE_TSCRATEMSR)) {
- tsc_scaling = false;
- } else {
- pr_info("TSC scaling supported\n");
- kvm_has_tsc_control = true;
- kvm_max_tsc_scaling_ratio = TSC_RATIO_MAX;
- kvm_tsc_scaling_ratio_frac_bits = 32;
- }
- }
-
- tsc_aux_uret_slot = kvm_add_user_return_msr(MSR_TSC_AUX);
-
- /* Check for pause filtering support */
- if (!boot_cpu_has(X86_FEATURE_PAUSEFILTER)) {
- pause_filter_count = 0;
- pause_filter_thresh = 0;
- } else if (!boot_cpu_has(X86_FEATURE_PFTHRESHOLD)) {
- pause_filter_thresh = 0;
- }
-
- if (nested) {
- printk(KERN_INFO "kvm: Nested Virtualization enabled\n");
- kvm_enable_efer_bits(EFER_SVME | EFER_LMSLE);
- }
-
- /*
- * KVM's MMU doesn't support using 2-level paging for itself, and thus
- * NPT isn't supported if the host is using 2-level paging since host
- * CR4 is unchanged on VMRUN.
- */
- if (!IS_ENABLED(CONFIG_X86_64) && !IS_ENABLED(CONFIG_X86_PAE))
- npt_enabled = false;
-
- if (!boot_cpu_has(X86_FEATURE_NPT))
- npt_enabled = false;
-
- /* Force VM NPT level equal to the host's paging level */
- kvm_configure_mmu(npt_enabled, get_npt_level(),
- get_npt_level(), PG_LEVEL_1G);
- pr_info("kvm: Nested Paging %sabled\n", npt_enabled ? "en" : "dis");
-
- /* Note, SEV setup consumes npt_enabled. */
- sev_hardware_setup();
-
- svm_hv_hardware_setup();
-
- svm_adjust_mmio_mask();
-
- for_each_possible_cpu(cpu) {
- r = svm_cpu_init(cpu);
- if (r)
- goto err;
- }
-
- if (nrips) {
- if (!boot_cpu_has(X86_FEATURE_NRIPS))
- nrips = false;
- }
-
- enable_apicv = avic = avic && npt_enabled && boot_cpu_has(X86_FEATURE_AVIC);
-
- if (enable_apicv) {
- pr_info("AVIC enabled\n");
-
- amd_iommu_register_ga_log_notifier(&avic_ga_log_notifier);
- }
-
- if (vls) {
- if (!npt_enabled ||
- !boot_cpu_has(X86_FEATURE_V_VMSAVE_VMLOAD) ||
- !IS_ENABLED(CONFIG_X86_64)) {
- vls = false;
- } else {
- pr_info("Virtual VMLOAD VMSAVE supported\n");
- }
- }
-
- if (boot_cpu_has(X86_FEATURE_SVME_ADDR_CHK))
- svm_gp_erratum_intercept = false;
-
- if (vgif) {
- if (!boot_cpu_has(X86_FEATURE_VGIF))
- vgif = false;
- else
- pr_info("Virtual GIF supported\n");
- }
-
- if (lbrv) {
- if (!boot_cpu_has(X86_FEATURE_LBRV))
- lbrv = false;
- else
- pr_info("LBR virtualization supported\n");
- }
-
- if (!pmu)
- pr_info("PMU virtualization is disabled\n");
-
- svm_set_cpu_caps();
-
- /*
- * It seems that on AMD processors PTE's accessed bit is
- * being set by the CPU hardware before the NPF vmexit.
- * This is not expected behaviour and our tests fail because
- * of it.
- * A workaround here is to disable support for
- * GUEST_MAXPHYADDR < HOST_MAXPHYADDR if NPT is enabled.
- * In this case userspace can know if there is support using
- * KVM_CAP_SMALLER_MAXPHYADDR extension and decide how to handle
- * it
- * If future AMD CPU models change the behaviour described above,
- * this variable can be changed accordingly
- */
- allow_smaller_maxphyaddr = !npt_enabled;
-
- return 0;
-
-err:
- svm_hardware_teardown();
- return r;
-}
-
static void init_seg(struct vmcb_seg *seg)
{
seg->selector = 0;
@@ -4714,6 +4481,239 @@ static struct kvm_x86_ops svm_x86_ops __initdata = {
.vcpu_deliver_sipi_vector = svm_vcpu_deliver_sipi_vector,
};

+/*
+ * The default MMIO mask is a single bit (excluding the present bit),
+ * which could conflict with the memory encryption bit. Check for
+ * memory encryption support and override the default MMIO mask if
+ * memory encryption is enabled.
+ */
+static __init void svm_adjust_mmio_mask(void)
+{
+ unsigned int enc_bit, mask_bit;
+ u64 msr, mask;
+
+ /* If there is no memory encryption support, use existing mask */
+ if (cpuid_eax(0x80000000) < 0x8000001f)
+ return;
+
+ /* If memory encryption is not enabled, use existing mask */
+ rdmsrl(MSR_AMD64_SYSCFG, msr);
+ if (!(msr & MSR_AMD64_SYSCFG_MEM_ENCRYPT))
+ return;
+
+ enc_bit = cpuid_ebx(0x8000001f) & 0x3f;
+ mask_bit = boot_cpu_data.x86_phys_bits;
+
+ /* Increment the mask bit if it is the same as the encryption bit */
+ if (enc_bit == mask_bit)
+ mask_bit++;
+
+ /*
+ * If the mask bit location is below 52, then some bits above the
+ * physical addressing limit will always be reserved, so use the
+ * rsvd_bits() function to generate the mask. This mask, along with
+ * the present bit, will be used to generate a page fault with
+ * PFER.RSV = 1.
+ *
+ * If the mask bit location is 52 (or above), then clear the mask.
+ */
+ mask = (mask_bit < 52) ? rsvd_bits(mask_bit, 51) | PT_PRESENT_MASK : 0;
+
+ kvm_mmu_set_mmio_spte_mask(mask, mask, PT_WRITABLE_MASK | PT_USER_MASK);
+}
+
+static __init void svm_set_cpu_caps(void)
+{
+ kvm_set_cpu_caps();
+
+ supported_xss = 0;
+
+ /* CPUID 0x80000001 and 0x8000000A (SVM features) */
+ if (nested) {
+ kvm_cpu_cap_set(X86_FEATURE_SVM);
+
+ if (nrips)
+ kvm_cpu_cap_set(X86_FEATURE_NRIPS);
+
+ if (npt_enabled)
+ kvm_cpu_cap_set(X86_FEATURE_NPT);
+
+ if (tsc_scaling)
+ kvm_cpu_cap_set(X86_FEATURE_TSCRATEMSR);
+
+ /* Nested VM can receive #VMEXIT instead of triggering #GP */
+ kvm_cpu_cap_set(X86_FEATURE_SVME_ADDR_CHK);
+ }
+
+ /* CPUID 0x80000008 */
+ if (boot_cpu_has(X86_FEATURE_LS_CFG_SSBD) ||
+ boot_cpu_has(X86_FEATURE_AMD_SSBD))
+ kvm_cpu_cap_set(X86_FEATURE_VIRT_SSBD);
+
+ /* AMD PMU PERFCTR_CORE CPUID */
+ if (pmu && boot_cpu_has(X86_FEATURE_PERFCTR_CORE))
+ kvm_cpu_cap_set(X86_FEATURE_PERFCTR_CORE);
+
+ /* CPUID 0x8000001F (SME/SEV features) */
+ sev_set_cpu_caps();
+}
+
+static __init int svm_hardware_setup(void)
+{
+ int cpu;
+ struct page *iopm_pages;
+ void *iopm_va;
+ int r;
+ unsigned int order = get_order(IOPM_SIZE);
+
+ /*
+ * NX is required for shadow paging and for NPT if the NX huge pages
+ * mitigation is enabled.
+ */
+ if (!boot_cpu_has(X86_FEATURE_NX)) {
+ pr_err_ratelimited("NX (Execute Disable) not supported\n");
+ return -EOPNOTSUPP;
+ }
+ kvm_enable_efer_bits(EFER_NX);
+
+ iopm_pages = alloc_pages(GFP_KERNEL, order);
+
+ if (!iopm_pages)
+ return -ENOMEM;
+
+ iopm_va = page_address(iopm_pages);
+ memset(iopm_va, 0xff, PAGE_SIZE * (1 << order));
+ iopm_base = page_to_pfn(iopm_pages) << PAGE_SHIFT;
+
+ init_msrpm_offsets();
+
+ supported_xcr0 &= ~(XFEATURE_MASK_BNDREGS | XFEATURE_MASK_BNDCSR);
+
+ if (boot_cpu_has(X86_FEATURE_FXSR_OPT))
+ kvm_enable_efer_bits(EFER_FFXSR);
+
+ if (tsc_scaling) {
+ if (!boot_cpu_has(X86_FEATURE_TSCRATEMSR)) {
+ tsc_scaling = false;
+ } else {
+ pr_info("TSC scaling supported\n");
+ kvm_has_tsc_control = true;
+ kvm_max_tsc_scaling_ratio = TSC_RATIO_MAX;
+ kvm_tsc_scaling_ratio_frac_bits = 32;
+ }
+ }
+
+ tsc_aux_uret_slot = kvm_add_user_return_msr(MSR_TSC_AUX);
+
+ /* Check for pause filtering support */
+ if (!boot_cpu_has(X86_FEATURE_PAUSEFILTER)) {
+ pause_filter_count = 0;
+ pause_filter_thresh = 0;
+ } else if (!boot_cpu_has(X86_FEATURE_PFTHRESHOLD)) {
+ pause_filter_thresh = 0;
+ }
+
+ if (nested) {
+ printk(KERN_INFO "kvm: Nested Virtualization enabled\n");
+ kvm_enable_efer_bits(EFER_SVME | EFER_LMSLE);
+ }
+
+ /*
+ * KVM's MMU doesn't support using 2-level paging for itself, and thus
+ * NPT isn't supported if the host is using 2-level paging since host
+ * CR4 is unchanged on VMRUN.
+ */
+ if (!IS_ENABLED(CONFIG_X86_64) && !IS_ENABLED(CONFIG_X86_PAE))
+ npt_enabled = false;
+
+ if (!boot_cpu_has(X86_FEATURE_NPT))
+ npt_enabled = false;
+
+ /* Force VM NPT level equal to the host's paging level */
+ kvm_configure_mmu(npt_enabled, get_npt_level(),
+ get_npt_level(), PG_LEVEL_1G);
+ pr_info("kvm: Nested Paging %sabled\n", npt_enabled ? "en" : "dis");
+
+ /* Note, SEV setup consumes npt_enabled. */
+ sev_hardware_setup();
+
+ svm_hv_hardware_setup();
+
+ svm_adjust_mmio_mask();
+
+ for_each_possible_cpu(cpu) {
+ r = svm_cpu_init(cpu);
+ if (r)
+ goto err;
+ }
+
+ if (nrips) {
+ if (!boot_cpu_has(X86_FEATURE_NRIPS))
+ nrips = false;
+ }
+
+ enable_apicv = avic = avic && npt_enabled && boot_cpu_has(X86_FEATURE_AVIC);
+
+ if (enable_apicv) {
+ pr_info("AVIC enabled\n");
+
+ amd_iommu_register_ga_log_notifier(&avic_ga_log_notifier);
+ }
+
+ if (vls) {
+ if (!npt_enabled ||
+ !boot_cpu_has(X86_FEATURE_V_VMSAVE_VMLOAD) ||
+ !IS_ENABLED(CONFIG_X86_64)) {
+ vls = false;
+ } else {
+ pr_info("Virtual VMLOAD VMSAVE supported\n");
+ }
+ }
+
+ if (boot_cpu_has(X86_FEATURE_SVME_ADDR_CHK))
+ svm_gp_erratum_intercept = false;
+
+ if (vgif) {
+ if (!boot_cpu_has(X86_FEATURE_VGIF))
+ vgif = false;
+ else
+ pr_info("Virtual GIF supported\n");
+ }
+
+ if (lbrv) {
+ if (!boot_cpu_has(X86_FEATURE_LBRV))
+ lbrv = false;
+ else
+ pr_info("LBR virtualization supported\n");
+ }
+
+ if (!pmu)
+ pr_info("PMU virtualization is disabled\n");
+
+ svm_set_cpu_caps();
+
+ /*
+ * It seems that on AMD processors PTE's accessed bit is
+ * being set by the CPU hardware before the NPF vmexit.
+ * This is not expected behaviour and our tests fail because
+ * of it.
+ * A workaround here is to disable support for
+ * GUEST_MAXPHYADDR < HOST_MAXPHYADDR if NPT is enabled.
+ * In this case userspace can know if there is support using
+ * KVM_CAP_SMALLER_MAXPHYADDR extension and decide how to handle
+ * it
+ * If future AMD CPU models change the behaviour described above,
+ * this variable can be changed accordingly
+ */
+ allow_smaller_maxphyaddr = !npt_enabled;
+
+ return 0;
+
+err:
+ svm_hardware_teardown();
+ return r;
+}
+
static struct kvm_x86_init_ops svm_init_ops __initdata = {
.cpu_has_kvm_support = has_svm,
.disabled_by_bios = is_disabled,
--
2.34.1.400.ga245620fadb-goog